build.gradle

@@ -1,18 +1,23 @@
 
 plugins {
+    id "checkstyle"
+    id "pmd"
     id 'maven-publish'
     id 'signing'
     id "io.github.gradle-nexus.publish-plugin" version "2.0.0-rc-1"
+    id "com.github.spotbugs" version "6.0.0-beta.3"
+    id "org.cyclonedx.bom" version "1.7.4"
+    id "org.xbib.gradle.plugin.asciidoctor" version "3.0.0"
 }
 
 wrapper {
     gradleVersion = libs.versions.gradle.get()
-    distributionType = Wrapper.DistributionType.BIN
+    distributionType = Wrapper.DistributionType.ALL
 }
 
 ext {
-    name = rootProject.name
     user = 'joerg'
+    name = 'datastructures'
     description = 'Data structures for Java'
     inceptionYear = '2012'
     url = 'https://xbib.org/' + user + '/' + name
@@ -26,10 +31,16 @@ ext {
 }
 
 subprojects {
+    //apply from: rootProject.file('gradle/ide/idea.gradle')
     apply from: rootProject.file('gradle/repositories/maven.gradle')
     apply from: rootProject.file('gradle/compile/java.gradle')
     apply from: rootProject.file('gradle/test/junit5.gradle')
+    apply from: rootProject.file('gradle/documentation/asciidoc.gradle')
+    apply from: rootProject.file('gradle/quality/checkstyle.gradle')
+    apply from: rootProject.file('gradle/quality/pmd.gradle')
+    //apply from: rootProject.file('gradle/quality/spotbugs.gradle')
     apply from: rootProject.file('gradle/publish/maven.gradle')
 }
 apply from: rootProject.file('gradle/publish/sonatype.gradle')
 apply from: rootProject.file('gradle/publish/forgejo.gradle')
+apply from: rootProject.file('gradle/quality/cyclonedx.gradle')

config/src/main/java/module-info.java

@@ -1,8 +1,12 @@
+import org.xbib.config.ConfigLogger;
+import org.xbib.config.NullConfigLogger;
+import org.xbib.config.SystemConfigLogger;
 import org.xbib.settings.SettingsLoader;
 
 module org.xbib.config {
     requires transitive org.xbib.settings.datastructures;
-    requires java.logging;
     exports org.xbib.config;
+    uses ConfigLogger;
     uses SettingsLoader;
+    provides ConfigLogger with NullConfigLogger, SystemConfigLogger;
 }

config/src/main/java/org/xbib/config/ConfigLoader.java

@@ -16,8 +16,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 import java.util.stream.Collectors;
 import org.xbib.settings.Settings;
 import org.xbib.settings.SettingsBuilder;
@@ -31,7 +29,7 @@ public class ConfigLoader {
 
     private static final Map<ConfigParams, Settings> map = new HashMap<>();
 
-    private static final Logger logger = Logger.getLogger(ConfigLoader.class.getName());
+    private ConfigLogger logger;
 
     private ConfigLoader() {
     }
@@ -40,6 +38,11 @@ public class ConfigLoader {
         return new ConfigLoader();
     }
 
+    public ConfigLoader withLogger(ConfigLogger logger) {
+        this.logger = logger;
+        return this;
+    }
+
     public synchronized Settings load(ConfigParams configParams) throws ConfigException {
         map.computeIfAbsent(configParams, p -> internalLoad(p)
                 .replacePropertyPlaceholders()
@@ -182,9 +185,13 @@ public class ConfigLoader {
             int pos = settingsFileName.lastIndexOf('.');
             String suffix = (pos > 0 ? settingsFileName.substring(pos + 1) : "").toLowerCase(Locale.ROOT);
             Path path = Paths.get(settingsFileName);
-            logger.log(Level.INFO, "trying " + path);
+            if (logger != null) {
+                logger.info("trying " + path);
+            }
             if (Files.exists(path)) {
-                logger.log(Level.INFO, "found path: " + path);
+                if (logger != null) {
+                    logger.info("found path: " + path);
+                }
                 System.setProperty("config.path", path.getParent().toString());
                 try {
                     InputStream inputStream = Files.newInputStream(path);
@@ -209,7 +216,9 @@ public class ConfigLoader {
                     params.directoryName + '-' + fileNameWithoutSuffix + suffix :  fileNameWithoutSuffix + suffix;
             InputStream inputStream = classLoader.getResourceAsStream(path);
             if (inputStream != null) {
-                logger.log(Level.INFO, "found resource: " + path);
+                if (logger != null) {
+                    logger.info("found resource: " + path);
+                }
                 SettingsBuilder streamSettings = createSettingsFromStream(inputStream, suffix);
                 if (streamSettings != null) {
                     settings.put(streamSettings.build());
@@ -222,7 +231,9 @@ public class ConfigLoader {
     private SettingsBuilder createSettingsFromStream(InputStream inputStream,
                                                      String suffix) throws ConfigException {
         if (inputStream == null) {
-            logger.log(Level.WARNING, "unable to open input stream");
+            if (logger != null) {
+                logger.error("unable to open input stream");
+            }
             return null;
         }
         return createSettingsFromReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8), suffix);
@@ -231,7 +242,9 @@ public class ConfigLoader {
     private SettingsBuilder createSettingsFromReader(Reader reader,
                                                      String suffix) throws ConfigException {
         if (reader == null) {
-            logger.log(Level.WARNING, "unable to open reader");
+            if (logger != null) {
+                logger.error("unable to open reader");
+            }
             return null;
         }
         SettingsLoader settingsLoader = SettingsLoaderService.getInstance().loaderFromResource(suffix);
@@ -245,7 +258,9 @@ public class ConfigLoader {
             }
             return settings;
         } else {
-            logger.log(Level.WARNING, "suffix is invalid: " + suffix);
+            if (logger != null) {
+                logger.error("suffix is invalid: " + suffix);
+            }
         }
         return null;
     }

config/src/main/java/org/xbib/config/ConfigLogger.java

@@ -0,0 +1,10 @@
+package org.xbib.config;
+
+public interface ConfigLogger {
+
+    void info(String string);
+
+    void warn(String string);
+
+    void error(String message);
+}

config/src/main/java/org/xbib/config/NullConfigLogger.java

@@ -0,0 +1,19 @@
+package org.xbib.config;
+
+public class NullConfigLogger implements ConfigLogger {
+
+    public NullConfigLogger() {
+    }
+
+    @Override
+    public void info(String string) {
+    }
+
+    @Override
+    public void warn(String message) {
+    }
+
+    @Override
+    public void error(String message) {
+    }
+}

config/src/main/java/org/xbib/config/SystemConfigLogger.java

@@ -0,0 +1,22 @@
+package org.xbib.config;
+
+public class SystemConfigLogger implements ConfigLogger {
+
+    public SystemConfigLogger() {
+    }
+
+    @Override
+    public void info(String string) {
+        System.err.println("info: " + string);
+    }
+
+    @Override
+    public void warn(String message) {
+        System.err.println("warning: " + message);
+    }
+
+    @Override
+    public void error(String message) {
+        System.err.println("error: " + message);
+    }
+}

config/src/main/java/org/xbib/config/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Classes for configuration setup.
+ */
+package org.xbib.config;

config/src/test/java/org/xbib/config/test/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Test classes for config.
+ */
+package org.xbib.config.test;

config/src/test/resources/META-INF/services/org.xbib.config.ConfigLogger

@@ -0,0 +1,2 @@
+org.xbib.config.NullConfigLogger
+org.xbib.config.SystemConfigLogger

datastructures-csv/src/test/java/org/xbib/datastructures/csv/test/GeneratorTest.java

@@ -39,14 +39,13 @@ public class GeneratorTest {
         StringWriter writer = new StringWriter();
         Generator gen = new Generator(writer);
         gen.keys(Arrays.asList("a", "b", "c"));
-        gen.writeKeys();
         for (int i = 0; i < 1; i++) {
             gen.write("val" + i);
             gen.write("\"Hello, World\"");
             gen.write("hey look a line seperator \n");
         }
         gen.close();
-        assertEquals("a,b,c,\nval0,\"\"\"Hello, World\"\"\",\"hey look a line seperator \n\"\n", writer.toString());
+        assertEquals("val0,\"\"\"Hello, World\"\"\",\"hey look a line seperator \n\"\n", writer.toString());
     }
 
     @Test

datastructures-immutable/src/main/java/org/xbib/datastructures/immutable/order/Ordering.java

@@ -695,7 +695,7 @@ public abstract class Ordering<T> implements Comparator<T> {
      * only when the resulting list may need further modification, or may contain {@code null}. The
      * input is not modified. The returned list has random access.
      *
-     * <p>Tthis method does not discard elements that are
+     * <p>Unlike {@link java.util.Sets#newTreeSet(Iterable)}, this method does not discard elements that are
      * duplicates according to the comparator. The sort performed is <i>stable</i>, meaning that such
      * elements will appear in the returned list in the same order they appeared in {@code elements}.
      *
@@ -716,7 +716,7 @@ public abstract class Ordering<T> implements Comparator<T> {
      * Returns an <b>immutable</b> list containing {@code elements} sorted by this ordering. The input
      * is not modified.
      *
-     * <p>This method does not discard elements that are
+     * <p>Unlike {@link java.util.Sets#newTreeSet(Iterable)}, this method does not discard elements that are
      * duplicates according to the comparator. The sort performed is <i>stable</i>, meaning that such
      * elements will appear in the returned list in the same order they appeared in {@code elements}.
      *
@@ -735,6 +735,10 @@ public abstract class Ordering<T> implements Comparator<T> {
      * Returns {@code true} if each element in {@code iterable} after the first is greater than or
      * equal to the element that preceded it, according to this ordering. Note that this is always
      * true when the iterable has fewer than two elements.
+     *
+     * <p><b>Java 8 users:</b> Use the equivalent {@link java.util.Comparators#isInOrder(Iterable, Comparator)}
+     * instead, since the rest of {@code Ordering} is mostly obsolete (as explained in the class
+     * documentation).
      */
     public boolean isOrdered(Iterable<? extends T> iterable) {
         Iterator<? extends T> it = iterable.iterator();
@@ -755,6 +759,10 @@ public abstract class Ordering<T> implements Comparator<T> {
      * Returns {@code true} if each element in {@code iterable} after the first is <i>strictly</i>
      * greater than the element that preceded it, according to this ordering. Note that this is always
      * true when the iterable has fewer than two elements.
+     *
+     * <p><b>Java 8 users:</b> Use the equivalent {@link java.util.Comparators#isInStrictOrder(Iterable,
+     * Comparator)} instead, since the rest of {@code Ordering} is mostly obsolete (as explained in
+     * the class documentation).
      */
     public boolean isStrictlyOrdered(Iterable<? extends T> iterable) {
         Iterator<? extends T> it = iterable.iterator();

datastructures-multi/build.gradle

@@ -0,0 +1,3 @@
+dependencies {
+    api project(':datastructures-immutable')
+}

datastructures-multi/src/main/java/module-info.java

@@ -0,0 +1,5 @@
+module org.xbib.datastructures.multi {
+    exports org.xbib.datastructures.multi;
+    requires org.xbib.datastructures.api;
+    requires org.xbib.datastructures.immutable;
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/AbstractMapBasedMultiset.java

@@ -0,0 +1,321 @@
+package org.xbib.datastructures.multi;
+
+import java.io.InvalidObjectException;
+import java.io.ObjectStreamException;
+import java.io.Serializable;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.ObjIntConsumer;
+import static java.util.Objects.requireNonNull;
+
+/**
+ * Basic implementation of {@code Multiset<E>} backed by an instance of {@code Map<E, Count>}.
+ *
+ * <p>For serialization to work, the subclass must specify explicit {@code readObject} and {@code
+ * writeObject} methods.
+ */
+abstract class AbstractMapBasedMultiset<E extends Object> extends AbstractMultiset<E>
+    implements Serializable {
+  // TODO(lowasser): consider overhauling this back to Map<E, Integer>
+  private transient Map<E, Count> backingMap;
+
+  /*
+   * Cache the size for efficiency. Using a long lets us avoid the need for
+   * overflow checking and ensures that size() will function correctly even if
+   * the multiset had once been larger than Integer.MAX_VALUE.
+   */
+  private transient long size;
+
+  /** Standard constructor. */
+  protected AbstractMapBasedMultiset(Map<E, Count> backingMap) {
+    checkArgument(backingMap.isEmpty());
+    this.backingMap = backingMap;
+  }
+
+  /** Used during deserialization only. The backing map must be empty. */
+  void setBackingMap(Map<E, Count> backingMap) {
+    this.backingMap = backingMap;
+  }
+
+  // Required Implementations
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>Invoking {@link Entry#getCount} on an entry in the returned set always returns the
+   * current count of that element in the multiset, as opposed to the count at the time the entry
+   * was retrieved.
+   */
+  @Override
+  public Set<Entry<E>> entrySet() {
+    return super.entrySet();
+  }
+
+  @Override
+  Iterator<E> elementIterator() {
+    final Iterator<Map.Entry<E, Count>> backingEntries = backingMap.entrySet().iterator();
+    return new Iterator<E>() {
+      @CheckForNull Map.Entry<E, Count> toRemove;
+
+      @Override
+      public boolean hasNext() {
+        return backingEntries.hasNext();
+      }
+
+      @Override
+      @ParametricNullness
+      public E next() {
+        final Map.Entry<E, Count> mapEntry = backingEntries.next();
+        toRemove = mapEntry;
+        return mapEntry.getKey();
+      }
+
+      @Override
+      public void remove() {
+        checkState(toRemove != null, "no calls to next() since the last call to remove()");
+        size -= toRemove.getValue().getAndSet(0);
+        backingEntries.remove();
+        toRemove = null;
+      }
+    };
+  }
+
+  @Override
+  Iterator<Entry<E>> entryIterator() {
+    final Iterator<Map.Entry<E, Count>> backingEntries = backingMap.entrySet().iterator();
+    return new Iterator<Entry<E>>() {
+      @CheckForNull Map.Entry<E, Count> toRemove;
+
+      @Override
+      public boolean hasNext() {
+        return backingEntries.hasNext();
+      }
+
+      @Override
+      public Entry<E> next() {
+        final Map.Entry<E, Count> mapEntry = backingEntries.next();
+        toRemove = mapEntry;
+        return new Multisets.AbstractEntry<E>() {
+          @Override
+          @ParametricNullness
+          public E getElement() {
+            return mapEntry.getKey();
+          }
+
+          @Override
+          public int getCount() {
+            Count count = mapEntry.getValue();
+            if (count == null || count.get() == 0) {
+              Count frequency = backingMap.get(getElement());
+              if (frequency != null) {
+                return frequency.get();
+              }
+            }
+            return (count == null) ? 0 : count.get();
+          }
+        };
+      }
+
+      @Override
+      public void remove() {
+        checkState(toRemove != null, "no calls to next() since the last call to remove()");
+        size -= toRemove.getValue().getAndSet(0);
+        backingEntries.remove();
+        toRemove = null;
+      }
+    };
+  }
+
+  @Override
+  public void forEachEntry(ObjIntConsumer<? super E> action) {
+    checkNotNull(action);
+    backingMap.forEach((element, count) -> action.accept(element, count.get()));
+  }
+
+  @Override
+  public void clear() {
+    for (Count frequency : backingMap.values()) {
+      frequency.set(0);
+    }
+    backingMap.clear();
+    size = 0L;
+  }
+
+  @Override
+  int distinctElements() {
+    return backingMap.size();
+  }
+
+  // Optimizations - Query Operations
+
+  @Override
+  public int size() {
+    return Ints.saturatedCast(size);
+  }
+
+  @Override
+  public Iterator<E> iterator() {
+    return new MapBasedMultisetIterator();
+  }
+
+  /*
+   * Not subclassing AbstractMultiset$MultisetIterator because next() needs to
+   * retrieve the Map.Entry<E, Count> entry, which can then be used for
+   * a more efficient remove() call.
+   */
+  private class MapBasedMultisetIterator implements Iterator<E> {
+    final Iterator<Map.Entry<E, Count>> entryIterator;
+    @CheckForNull Map.Entry<E, Count> currentEntry;
+    int occurrencesLeft;
+    boolean canRemove;
+
+    MapBasedMultisetIterator() {
+      this.entryIterator = backingMap.entrySet().iterator();
+    }
+
+    @Override
+    public boolean hasNext() {
+      return occurrencesLeft > 0 || entryIterator.hasNext();
+    }
+
+    @Override
+    @ParametricNullness
+    public E next() {
+      if (occurrencesLeft == 0) {
+        currentEntry = entryIterator.next();
+        occurrencesLeft = currentEntry.getValue().get();
+      }
+      occurrencesLeft--;
+      canRemove = true;
+      /*
+       * requireNonNull is safe because occurrencesLeft starts at 0, forcing us to initialize
+       * currentEntry above. After that, we never clear it.
+       */
+      return requireNonNull(currentEntry).getKey();
+    }
+
+    @Override
+    public void remove() {
+      checkRemove(canRemove);
+      /*
+       * requireNonNull is safe because canRemove is set to true only after we initialize
+       * currentEntry (which we never subsequently clear).
+       */
+      int frequency = requireNonNull(currentEntry).getValue().get();
+      if (frequency <= 0) {
+        throw new ConcurrentModificationException();
+      }
+      if (currentEntry.getValue().addAndGet(-1) == 0) {
+        entryIterator.remove();
+      }
+      size--;
+      canRemove = false;
+    }
+  }
+
+  @Override
+  public int count(@CheckForNull Object element) {
+    Count frequency = Maps.safeGet(backingMap, element);
+    return (frequency == null) ? 0 : frequency.get();
+  }
+
+  // Optional Operations - Modification Operations
+
+  /**
+   * {@inheritDoc}
+   *
+   * @throws IllegalArgumentException if the call would result in more than {@link
+   *     Integer#MAX_VALUE} occurrences of {@code element} in this multiset.
+   */
+  @CanIgnoreReturnValue
+  @Override
+  public int add(@ParametricNullness E element, int occurrences) {
+    if (occurrences == 0) {
+      return count(element);
+    }
+    checkArgument(occurrences > 0, "occurrences cannot be negative: %s", occurrences);
+    Count frequency = backingMap.get(element);
+    int oldCount;
+    if (frequency == null) {
+      oldCount = 0;
+      backingMap.put(element, new Count(occurrences));
+    } else {
+      oldCount = frequency.get();
+      long newCount = (long) oldCount + (long) occurrences;
+      checkArgument(newCount <= Integer.MAX_VALUE, "too many occurrences: %s", newCount);
+      frequency.add(occurrences);
+    }
+    size += occurrences;
+    return oldCount;
+  }
+
+  @CanIgnoreReturnValue
+  @Override
+  public int remove(@CheckForNull Object element, int occurrences) {
+    if (occurrences == 0) {
+      return count(element);
+    }
+    checkArgument(occurrences > 0, "occurrences cannot be negative: %s", occurrences);
+    Count frequency = backingMap.get(element);
+    if (frequency == null) {
+      return 0;
+    }
+
+    int oldCount = frequency.get();
+
+    int numberRemoved;
+    if (oldCount > occurrences) {
+      numberRemoved = occurrences;
+    } else {
+      numberRemoved = oldCount;
+      backingMap.remove(element);
+    }
+
+    frequency.add(-numberRemoved);
+    size -= numberRemoved;
+    return oldCount;
+  }
+
+  // Roughly a 33% performance improvement over AbstractMultiset.setCount().
+  @CanIgnoreReturnValue
+  @Override
+  public int setCount(@ParametricNullness E element, int count) {
+    checkNonnegative(count, "count");
+
+    Count existingCounter;
+    int oldCount;
+    if (count == 0) {
+      existingCounter = backingMap.remove(element);
+      oldCount = getAndSet(existingCounter, count);
+    } else {
+      existingCounter = backingMap.get(element);
+      oldCount = getAndSet(existingCounter, count);
+
+      if (existingCounter == null) {
+        backingMap.put(element, new Count(count));
+      }
+    }
+
+    size += (count - oldCount);
+    return oldCount;
+  }
+
+  private static int getAndSet(@CheckForNull Count i, int count) {
+    if (i == null) {
+      return 0;
+    }
+
+    return i.getAndSet(count);
+  }
+
+  // Don't allow default serialization.
+  @GwtIncompatible // java.io.ObjectStreamException
+  private void readObjectNoData() throws ObjectStreamException {
+    throw new InvalidObjectException("Stream data required");
+  }
+
+  @GwtIncompatible // not needed in emulated source.
+  private static final long serialVersionUID = -2250766705698539974L;
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/AbstractMultimap.java

@@ -0,0 +1,295 @@
+package org.xbib.datastructures.multi;
+
+import java.util.AbstractCollection;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Objects;
+import java.util.Set;
+import java.util.Spliterator;
+import java.util.Spliterators;
+import org.xbib.datastructures.api.Multimap;
+import org.xbib.datastructures.api.Multiset;
+import org.xbib.datastructures.api.SetMultimap;
+
+/**
+ * A skeleton {@code Multimap} implementation, not necessarily in terms of a {@code Map}.
+ */
+abstract class AbstractMultimap<K extends Object, V extends Object>
+        implements Multimap<K, V> {
+    @Override
+    public boolean isEmpty() {
+        return size() == 0;
+    }
+
+    @Override
+    public boolean containsValue(Object value) {
+        for (Collection<V> collection : asMap().values()) {
+            if (collection.contains(value)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    @Override
+    public boolean containsEntry(Object key, Object value) {
+        Collection<V> collection = asMap().get(key);
+        return collection != null && collection.contains(value);
+    }
+
+    @Override
+    public boolean remove(Object key, Object value) {
+        Collection<V> collection = asMap().get(key);
+        return collection != null && collection.remove(value);
+    }
+
+    @Override
+    public boolean put(K key, V value) {
+        return get(key).add(value);
+    }
+
+    @Override
+    public boolean putAll(K key, Iterable<? extends V> values) {
+        Objects.requireNonNull(values);
+        // make sure we only call values.iterator() once
+        // and we only call get(key) if values is nonempty
+        if (values instanceof Collection<? extends V> valueCollection) {
+            return !valueCollection.isEmpty() && get(key).addAll(valueCollection);
+        } else {
+            Iterator<? extends V> valueItr = values.iterator();
+            return valueItr.hasNext() && addAll(get(key), valueItr);
+        }
+    }
+
+    @Override
+    public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
+        boolean changed = false;
+        for (Entry<? extends K, ? extends V> entry : multimap.entries()) {
+            changed |= put(entry.getKey(), entry.getValue());
+        }
+        return changed;
+    }
+
+    @Override
+    public Collection<V> replaceValues(K key, Iterable<? extends V> values) {
+        Objects.requireNonNull(values);
+        Collection<V> result = removeAll(key);
+        putAll(key, values);
+        return result;
+    }
+
+    private transient Collection<Entry<K, V>> entries;
+
+    @Override
+    public Collection<Entry<K, V>> entries() {
+        Collection<Entry<K, V>> result = entries;
+        return (result == null) ? entries = createEntries() : result;
+    }
+
+    abstract Collection<Entry<K, V>> createEntries();
+
+    class Entries extends MultimapsEntries<K, V> {
+        @Override
+        Multimap<K, V> multimap() {
+            return AbstractMultimap.this;
+        }
+
+        @Override
+        public Iterator<Entry<K, V>> iterator() {
+            return entryIterator();
+        }
+
+        @Override
+        public Spliterator<Entry<K, V>> spliterator() {
+            return entrySpliterator();
+        }
+    }
+
+    class EntrySet extends Entries implements Set<Entry<K, V>> {
+        @Override
+        public int hashCode() {
+            return hashCodeImpl(this);
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            return equalsImpl(this, obj);
+        }
+    }
+
+    abstract Iterator<Entry<K, V>> entryIterator();
+
+    Spliterator<Entry<K, V>> entrySpliterator() {
+        return Spliterators.spliterator(
+                entryIterator(), size(), (this instanceof SetMultimap) ? Spliterator.DISTINCT : 0);
+    }
+
+    private transient Set<K> keySet;
+
+    @Override
+    public Set<K> keySet() {
+        Set<K> result = keySet;
+        return (result == null) ? keySet = createKeySet() : result;
+    }
+
+    abstract Set<K> createKeySet();
+
+    private transient Multiset<K> keys;
+
+    @Override
+    public Multiset<K> keys() {
+        Multiset<K> result = keys;
+        return (result == null) ? keys = createKeys() : result;
+    }
+
+    abstract Multiset<K> createKeys();
+
+    private transient Collection<V> values;
+
+    @Override
+    public Collection<V> values() {
+        Collection<V> result = values;
+        return (result == null) ? values = createValues() : result;
+    }
+
+    abstract Collection<V> createValues();
+
+    class Values extends AbstractCollection<V> {
+        @Override
+        public Iterator<V> iterator() {
+            return valueIterator();
+        }
+
+        @Override
+        public Spliterator<V> spliterator() {
+            return valueSpliterator();
+        }
+
+        @Override
+        public int size() {
+            return AbstractMultimap.this.size();
+        }
+
+        @Override
+        public boolean contains(Object o) {
+            return AbstractMultimap.this.containsValue(o);
+        }
+
+        @Override
+        public void clear() {
+            AbstractMultimap.this.clear();
+        }
+    }
+
+    Iterator<V> valueIterator() {
+        return valueIterator(entries().iterator());
+    }
+
+    Spliterator<V> valueSpliterator() {
+        return Spliterators.spliterator(valueIterator(), size(), 0);
+    }
+
+    private transient Map<K, Collection<V>> asMap;
+
+    @Override
+    public Map<K, Collection<V>> asMap() {
+        Map<K, Collection<V>> result = asMap;
+        return (result == null) ? asMap = createAsMap() : result;
+    }
+
+    abstract Map<K, Collection<V>> createAsMap();
+
+    // Comparison and hashing
+
+    @Override
+    public boolean equals(Object object) {
+        return equalsImpl(this, object);
+    }
+
+    /**
+     * Returns the hash code for this multimap.
+     *
+     * <p>The hash code of a multimap is defined as the hash code of the map view, as returned by
+     * {@link Multimap#asMap}.
+     *
+     * @see Map#hashCode
+     */
+    @Override
+    public int hashCode() {
+        return asMap().hashCode();
+    }
+
+    /**
+     * Returns a string representation of the multimap, generated by calling {@code toString} on the
+     * map returned by {@link Multimap#asMap}.
+     *
+     * @return a string representation of the multimap
+     */
+    @Override
+    public String toString() {
+        return asMap().toString();
+    }
+
+    private static <K extends Object, V extends Object> Iterator<V> valueIterator(Iterator<Entry<K, V>> entryIterator) {
+        return new TransformedIterator<Entry<K, V>, V>(entryIterator) {
+            @Override
+            V transform(Entry<K, V> entry) {
+                return entry.getValue();
+            }
+        };
+    }
+
+    private static <T extends Object> boolean addAll(
+            Collection<T> addTo, Iterator<? extends T> iterator) {
+        Objects.requireNonNull(addTo);
+        Objects.requireNonNull(iterator);
+        boolean wasModified = false;
+        while (iterator.hasNext()) {
+            wasModified |= addTo.add(iterator.next());
+        }
+        return wasModified;
+    }
+
+    /** An implementation for {@link Set#hashCode()}. */
+    static int hashCodeImpl(Set<?> s) {
+        int hashCode = 0;
+        for (Object o : s) {
+            hashCode += o != null ? o.hashCode() : 0;
+
+            hashCode = ~~hashCode;
+            // Needed to deal with unusual integer overflow in GWT.
+        }
+        return hashCode;
+    }
+
+    /** An implementation for {@link Set#equals(Object)}. */
+    private static boolean equalsImpl(Set<?> s, Object object) {
+        if (s == object) {
+            return true;
+        }
+        if (object instanceof Set) {
+            Set<?> o = (Set<?>) object;
+
+            try {
+                return s.size() == o.size() && s.containsAll(o);
+            } catch (NullPointerException | ClassCastException ignored) {
+                return false;
+            }
+        }
+        return false;
+    }
+
+    static boolean equalsImpl(Multimap<?, ?> multimap, Object object) {
+        if (object == multimap) {
+            return true;
+        }
+        if (object instanceof Multimap) {
+            Multimap<?, ?> that = (Multimap<?, ?>) object;
+            return multimap.asMap().equals(that.asMap());
+        }
+        return false;
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/AbstractMultiset.java

@@ -0,0 +1,234 @@
+/*
+ * Copyright (C) 2007 The Guava Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.xbib.datastructures.multi;
+
+import com.google.common.annotations.GwtCompatible;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
+import com.google.errorprone.annotations.concurrent.LazyInit;
+import com.google.j2objc.annotations.WeakOuter;
+import java.util.AbstractCollection;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Set;
+import javax.annotation.CheckForNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.xbib.datastructures.api.Multiset;
+import static com.google.common.collect.Multisets.setCountImpl;
+
+/**
+ * This class provides a skeletal implementation of the {@link Multiset} interface. A new multiset
+ * implementation can be created easily by extending this class and implementing the {@link
+ * Multiset#entrySet()} method, plus optionally overriding {@link #add(Object, int)} and {@link
+ * #remove(Object, int)} to enable modifications to the multiset.
+ *
+ * <p>The {@link #count} and {@link #size} implementations all iterate across the set returned by
+ * {@link Multiset#entrySet()}, as do many methods acting on the set returned by {@link
+ * #elementSet()}. Override those methods for better performance.
+ *
+ * @author Kevin Bourrillion
+ * @author Louis Wasserman
+ */
+@GwtCompatible
+@ElementTypesAreNonnullByDefault
+abstract class AbstractMultiset<E extends @Nullable Object> extends AbstractCollection<E>
+    implements Multiset<E> {
+  // Query Operations
+
+  @Override
+  public boolean isEmpty() {
+    return entrySet().isEmpty();
+  }
+
+  @Override
+  public boolean contains(@CheckForNull Object element) {
+    return count(element) > 0;
+  }
+
+  // Modification Operations
+  @CanIgnoreReturnValue
+  @Override
+  public final boolean add(@ParametricNullness E element) {
+    add(element, 1);
+    return true;
+  }
+
+  @CanIgnoreReturnValue
+  @Override
+  public int add(@ParametricNullness E element, int occurrences) {
+    throw new UnsupportedOperationException();
+  }
+
+  @CanIgnoreReturnValue
+  @Override
+  public final boolean remove(@CheckForNull Object element) {
+    return remove(element, 1) > 0;
+  }
+
+  @CanIgnoreReturnValue
+  @Override
+  public int remove(@CheckForNull Object element, int occurrences) {
+    throw new UnsupportedOperationException();
+  }
+
+  @CanIgnoreReturnValue
+  @Override
+  public int setCount(@ParametricNullness E element, int count) {
+    return setCountImpl(this, element, count);
+  }
+
+  @CanIgnoreReturnValue
+  @Override
+  public boolean setCount(@ParametricNullness E element, int oldCount, int newCount) {
+    return setCountImpl(this, element, oldCount, newCount);
+  }
+
+  // Bulk Operations
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>This implementation is highly efficient when {@code elementsToAdd} is itself a {@link
+   * Multiset}.
+   */
+  @CanIgnoreReturnValue
+  @Override
+  public final boolean addAll(Collection<? extends E> elementsToAdd) {
+    return Multisets.addAllImpl(this, elementsToAdd);
+  }
+
+  @CanIgnoreReturnValue
+  @Override
+  public final boolean removeAll(Collection<?> elementsToRemove) {
+    return Multisets.removeAllImpl(this, elementsToRemove);
+  }
+
+  @CanIgnoreReturnValue
+  @Override
+  public final boolean retainAll(Collection<?> elementsToRetain) {
+    return Multisets.retainAllImpl(this, elementsToRetain);
+  }
+
+  @Override
+  public abstract void clear();
+
+  // Views
+
+  @LazyInit @CheckForNull private transient Set<E> elementSet;
+
+  @Override
+  public Set<E> elementSet() {
+    Set<E> result = elementSet;
+    if (result == null) {
+      elementSet = result = createElementSet();
+    }
+    return result;
+  }
+
+  /**
+   * Creates a new instance of this multiset's element set, which will be returned by {@link
+   * #elementSet()}.
+   */
+  Set<E> createElementSet() {
+    return new ElementSet();
+  }
+
+  @WeakOuter
+  class ElementSet extends Multisets.ElementSet<E> {
+    @Override
+    Multiset<E> multiset() {
+      return AbstractMultiset.this;
+    }
+
+    @Override
+    public Iterator<E> iterator() {
+      return elementIterator();
+    }
+  }
+
+  abstract Iterator<E> elementIterator();
+
+  @LazyInit @CheckForNull private transient Set<Entry<E>> entrySet;
+
+  @Override
+  public Set<Entry<E>> entrySet() {
+    Set<Entry<E>> result = entrySet;
+    if (result == null) {
+      entrySet = result = createEntrySet();
+    }
+    return result;
+  }
+
+  @WeakOuter
+  class EntrySet extends Multisets.EntrySet<E> {
+    @Override
+    Multiset<E> multiset() {
+      return AbstractMultiset.this;
+    }
+
+    @Override
+    public Iterator<Entry<E>> iterator() {
+      return entryIterator();
+    }
+
+    @Override
+    public int size() {
+      return distinctElements();
+    }
+  }
+
+  Set<Entry<E>> createEntrySet() {
+    return new EntrySet();
+  }
+
+  abstract Iterator<Entry<E>> entryIterator();
+
+  abstract int distinctElements();
+
+  // Object methods
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>This implementation returns {@code true} if {@code object} is a multiset of the same size
+   * and if, for each element, the two multisets have the same count.
+   */
+  @Override
+  public final boolean equals(@CheckForNull Object object) {
+    return Multisets.equalsImpl(this, object);
+  }
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>This implementation returns the hash code of {@link Multiset#entrySet()}.
+   */
+  @Override
+  public final int hashCode() {
+    return entrySet().hashCode();
+  }
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>This implementation returns the result of invoking {@code toString} on {@link
+   * Multiset#entrySet()}.
+   */
+  @Override
+  public final String toString() {
+    return entrySet().toString();
+  }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/AbstractSetMultimap.java

@@ -0,0 +1,126 @@
+package org.xbib.datastructures.multi;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+import org.xbib.datastructures.api.Multimap;
+import org.xbib.datastructures.api.SetMultimap;
+
+/**
+ * Basic implementation of the {@link SetMultimap} interface. It's a wrapper around {@link
+ * AbstractMapBasedMultimap} that converts the returned collections into {@code Sets}. The {@link
+ * #createCollection} method must return a {@code Set}.
+ */
+abstract class AbstractSetMultimap<K extends Object, V extends Object>
+    extends AbstractMapBasedMultimap<K, V> implements SetMultimap<K, V> {
+  /**
+   * Creates a new multimap that uses the provided map.
+   *
+   * @param map place to store the mapping from each key to its corresponding values
+   */
+  protected AbstractSetMultimap(Map<K, Collection<V>> map) {
+    super(map);
+  }
+
+  @Override
+  abstract Set<V> createCollection();
+
+  @Override
+  Set<V> createUnmodifiableEmptyCollection() {
+    return Collections.emptySet();
+  }
+
+  @Override
+  <E extends Object> Collection<E> unmodifiableCollectionSubclass(
+      Collection<E> collection) {
+    return Collections.unmodifiableSet((Set<E>) collection);
+  }
+
+  @Override
+  Collection<V> wrapCollection(K key, Collection<V> collection) {
+    return new WrappedSet(key, (Set<V>) collection);
+  }
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>Because a {@code SetMultimap} has unique values for a given key, this method returns a
+   * {@link Set}, instead of the {@link Collection} specified in the {@link Multimap} interface.
+   */
+  @Override
+  public Set<V> get(K key) {
+    return (Set<V>) super.get(key);
+  }
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>Because a {@code SetMultimap} has unique values for a given key, this method returns a
+   * {@link Set}, instead of the {@link Collection} specified in the {@link Multimap} interface.
+   */
+  @Override
+  public Set<Entry<K, V>> entries() {
+    return (Set<Entry<K, V>>) super.entries();
+  }
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>Because a {@code SetMultimap} has unique values for a given key, this method returns a
+   * {@link Set}, instead of the {@link Collection} specified in the {@link Multimap} interface.
+   */
+  @Override
+  public Set<V> removeAll(Object key) {
+    return (Set<V>) super.removeAll(key);
+  }
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>Because a {@code SetMultimap} has unique values for a given key, this method returns a
+   * {@link Set}, instead of the {@link Collection} specified in the {@link Multimap} interface.
+   *
+   * <p>Any duplicates in {@code values} will be stored in the multimap once.
+   */
+  @Override
+  public Set<V> replaceValues(K key, Iterable<? extends V> values) {
+    return (Set<V>) super.replaceValues(key, values);
+  }
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>Though the method signature doesn't say so explicitly, the returned map has {@link Set}
+   * values.
+   */
+  @Override
+  public Map<K, Collection<V>> asMap() {
+    return super.asMap();
+  }
+
+  /**
+   * Stores a key-value pair in the multimap.
+   *
+   * @param key key to store in the multimap
+   * @param value value to store in the multimap
+   * @return {@code true} if the method increased the size of the multimap, or {@code false} if the
+   *     multimap already contained the key-value pair
+   */
+  @Override
+  public boolean put(K key, V value) {
+    return super.put(key, value);
+  }
+
+  /**
+   * Compares the specified object to this multimap for equality.
+   *
+   * <p>Two {@code SetMultimap} instances are equal if, for each key, they contain the same values.
+   * Equality does not depend on the ordering of keys or values.
+   */
+  @Override
+  public boolean equals(Object object) {
+    return super.equals(object);
+  }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/BaseImmutableMultimap.java

@@ -0,0 +1,8 @@
+package org.xbib.datastructures.multi;
+
+/**
+ * A dummy superclass of {@link ImmutableMultimap} that can be instanceof'd without ProGuard
+ * retaining additional implementation details of {@link ImmutableMultimap}.
+ */
+abstract class BaseImmutableMultimap<K, V> extends AbstractMultimap<K, V> {
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/ImmutableListMultimap.java

@@ -0,0 +1,426 @@
+package org.xbib.datastructures.multi;
+
+import java.io.IOException;
+import java.io.InvalidObjectException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Map.Entry;
+import java.util.function.Function;
+import java.util.stream.Collector;
+import java.util.stream.Stream;
+import org.xbib.datastructures.api.ListMultimap;
+import org.xbib.datastructures.api.Multimap;
+
+/**
+ * A {@link ListMultimap} whose contents will never change, with many other important properties
+ * detailed at {@link ImmutableCollection}.
+ *
+ */
+public class ImmutableListMultimap<K, V> extends ImmutableMultimap<K, V>
+    implements ListMultimap<K, V> {
+  /**
+   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableListMultimap}
+   * whose keys and values are the result of applying the provided mapping functions to the input
+   * elements.
+   *
+   * <p>For streams with defined encounter order (as defined in the Ordering section of the {@link
+   * java.util.stream} Javadoc), that order is preserved, but entries are <a
+   * href="ImmutableMultimap.html#iteration">grouped by key</a>.
+   *
+   * <p>Example:
+   *
+   * <pre>{@code
+   * static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
+   *     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
+   *         .collect(toImmutableListMultimap(str -> str.charAt(0), str -> str.substring(1)));
+   *
+   * // is equivalent to
+   *
+   * static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
+   *     new ImmutableListMultimap.Builder<Character, String>()
+   *         .put('b', "anana")
+   *         .putAll('a', "pple", "sparagus")
+   *         .putAll('c', "arrot", "herry")
+   *         .build();
+   * }</pre>
+   *
+   * @since 21.0
+   */
+  public static <T extends Object, K, V>
+      Collector<T, ?, ImmutableListMultimap<K, V>> toImmutableListMultimap(
+          Function<? super T, ? extends K> keyFunction,
+          Function<? super T, ? extends V> valueFunction) {
+    return CollectCollectors.toImmutableListMultimap(keyFunction, valueFunction);
+  }
+
+  /**
+   * Returns a {@code Collector} accumulating entries into an {@code ImmutableListMultimap}. Each
+   * input element is mapped to a key and a stream of values, each of which are put into the
+   * resulting {@code Multimap}, in the encounter order of the stream and the encounter order of the
+   * streams of values.
+   *
+   * <p>Example:
+   *
+   * <pre>{@code
+   * static final ImmutableListMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
+   *     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
+   *         .collect(
+   *             flatteningToImmutableListMultimap(
+   *                  str -> str.charAt(0),
+   *                  str -> str.substring(1).chars().mapToObj(c -> (char) c));
+   *
+   * // is equivalent to
+   *
+   * static final ImmutableListMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
+   *     ImmutableListMultimap.<Character, Character>builder()
+   *         .putAll('b', Arrays.asList('a', 'n', 'a', 'n', 'a'))
+   *         .putAll('a', Arrays.asList('p', 'p', 'l', 'e'))
+   *         .putAll('c', Arrays.asList('a', 'r', 'r', 'o', 't'))
+   *         .putAll('a', Arrays.asList('s', 'p', 'a', 'r', 'a', 'g', 'u', 's'))
+   *         .putAll('c', Arrays.asList('h', 'e', 'r', 'r', 'y'))
+   *         .build();
+   * }
+   * }</pre>
+   *
+   * @since 21.0
+   */
+  public static <T extends Object, K, V>
+      Collector<T, ?, ImmutableListMultimap<K, V>> flatteningToImmutableListMultimap(
+          Function<? super T, ? extends K> keyFunction,
+          Function<? super T, ? extends Stream<? extends V>> valuesFunction) {
+    return CollectCollectors.flatteningToImmutableListMultimap(keyFunction, valuesFunction);
+  }
+
+  /**
+   * Returns the empty multimap.
+   *
+   * <p><b>Performance note:</b> the instance returned is a singleton.
+   */
+  // Casting is safe because the multimap will never hold any elements.
+  @SuppressWarnings("unchecked")
+  public static <K, V> ImmutableListMultimap<K, V> of() {
+    return (ImmutableListMultimap<K, V>) EmptyImmutableListMultimap.INSTANCE;
+  }
+
+  /** Returns an immutable multimap containing a single entry. */
+  public static <K, V> ImmutableListMultimap<K, V> of(K k1, V v1) {
+    Builder<K, V> builder = ImmutableListMultimap.builder();
+    builder.put(k1, v1);
+    return builder.build();
+  }
+
+  /** Returns an immutable multimap containing the given entries, in order. */
+  public static <K, V> ImmutableListMultimap<K, V> of(K k1, V v1, K k2, V v2) {
+    Builder<K, V> builder = ImmutableListMultimap.builder();
+    builder.put(k1, v1);
+    builder.put(k2, v2);
+    return builder.build();
+  }
+
+  /** Returns an immutable multimap containing the given entries, in order. */
+  public static <K, V> ImmutableListMultimap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3) {
+    Builder<K, V> builder = ImmutableListMultimap.builder();
+    builder.put(k1, v1);
+    builder.put(k2, v2);
+    builder.put(k3, v3);
+    return builder.build();
+  }
+
+  /** Returns an immutable multimap containing the given entries, in order. */
+  public static <K, V> ImmutableListMultimap<K, V> of(
+      K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
+    Builder<K, V> builder = ImmutableListMultimap.builder();
+    builder.put(k1, v1);
+    builder.put(k2, v2);
+    builder.put(k3, v3);
+    builder.put(k4, v4);
+    return builder.build();
+  }
+
+  /** Returns an immutable multimap containing the given entries, in order. */
+  public static <K, V> ImmutableListMultimap<K, V> of(
+      K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
+    Builder<K, V> builder = ImmutableListMultimap.builder();
+    builder.put(k1, v1);
+    builder.put(k2, v2);
+    builder.put(k3, v3);
+    builder.put(k4, v4);
+    builder.put(k5, v5);
+    return builder.build();
+  }
+
+  // looking for of() with > 5 entries? Use the builder instead.
+
+  /**
+   * Returns a new builder. The generated builder is equivalent to the builder created by the {@link
+   * Builder} constructor.
+   */
+  public static <K, V> Builder<K, V> builder() {
+    return new Builder<>();
+  }
+
+  /**
+   * A builder for creating immutable {@code ListMultimap} instances, especially {@code public
+   * static final} multimaps ("constant multimaps"). Example:
+   *
+   * <pre>{@code
+   * static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
+   *     new ImmutableListMultimap.Builder<String, Integer>()
+   *         .put("one", 1)
+   *         .putAll("several", 1, 2, 3)
+   *         .putAll("many", 1, 2, 3, 4, 5)
+   *         .build();
+   * }</pre>
+   *
+   * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build
+   * multiple multimaps in series. Each multimap contains the key-value mappings in the previously
+   * created multimaps.
+   */
+  public static final class Builder<K, V> extends ImmutableMultimap.Builder<K, V> {
+    /**
+     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
+     * ImmutableListMultimap#builder}.
+     */
+    public Builder() {}
+
+    @Override
+    public Builder<K, V> put(K key, V value) {
+      super.put(key, value);
+      return this;
+    }
+
+    @Override
+    public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
+      super.put(entry);
+      return this;
+    }
+
+    @Override
+    public Builder<K, V> putAll(Iterable<? extends Entry<? extends K, ? extends V>> entries) {
+      super.putAll(entries);
+      return this;
+    }
+
+    @Override
+    public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
+      super.putAll(key, values);
+      return this;
+    }
+
+    @Override
+    public Builder<K, V> putAll(K key, V... values) {
+      super.putAll(key, values);
+      return this;
+    }
+
+    @Override
+    public Builder<K, V> putAll(Multimap<? extends K, ? extends V> multimap) {
+      super.putAll(multimap);
+      return this;
+    }
+
+    @Override
+    Builder<K, V> combine(ImmutableMultimap.Builder<K, V> other) {
+      super.combine(other);
+      return this;
+    }
+
+    @Override
+    public Builder<K, V> orderKeysBy(Comparator<? super K> keyComparator) {
+      super.orderKeysBy(keyComparator);
+      return this;
+    }
+
+    @Override
+    public Builder<K, V> orderValuesBy(Comparator<? super V> valueComparator) {
+      super.orderValuesBy(valueComparator);
+      return this;
+    }
+
+    /** Returns a newly-created immutable list multimap. */
+    @Override
+    public ImmutableListMultimap<K, V> build() {
+      return (ImmutableListMultimap<K, V>) super.build();
+    }
+  }
+
+  /**
+   * Returns an immutable multimap containing the same mappings as {@code multimap}. The generated
+   * multimap's key and value orderings correspond to the iteration ordering of the {@code
+   * multimap.asMap()} view.
+   *
+   * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
+   * safe to do so. The exact circumstances under which a copy will or will not be performed are
+   * undocumented and subject to change.
+   *
+   * @throws NullPointerException if any key or value in {@code multimap} is null
+   */
+  public static <K, V> ImmutableListMultimap<K, V> copyOf(
+      Multimap<? extends K, ? extends V> multimap) {
+    if (multimap.isEmpty()) {
+      return of();
+    }
+
+    // TODO(lowasser): copy ImmutableSetMultimap by using asList() on the sets
+    if (multimap instanceof ImmutableListMultimap) {
+      @SuppressWarnings("unchecked") // safe since multimap is not writable
+      ImmutableListMultimap<K, V> kvMultimap = (ImmutableListMultimap<K, V>) multimap;
+      if (!kvMultimap.isPartialView()) {
+        return kvMultimap;
+      }
+    }
+
+    return fromMapEntries(multimap.asMap().entrySet(), null);
+  }
+
+  /**
+   * Returns an immutable multimap containing the specified entries. The returned multimap iterates
+   * over keys in the order they were first encountered in the input, and the values for each key
+   * are iterated in the order they were encountered.
+   *
+   * @throws NullPointerException if any key, value, or entry is null
+   */
+  public static <K, V> ImmutableListMultimap<K, V> copyOf(
+      Iterable<? extends Entry<? extends K, ? extends V>> entries) {
+    return new Builder<K, V>().putAll(entries).build();
+  }
+
+  /** Creates an ImmutableListMultimap from an asMap.entrySet. */
+  static <K, V> ImmutableListMultimap<K, V> fromMapEntries(
+      Collection<? extends Entry<? extends K, ? extends Collection<? extends V>>> mapEntries,
+      Comparator<? super V> valueComparator) {
+    if (mapEntries.isEmpty()) {
+      return of();
+    }
+    ImmutableMap.Builder<K, ImmutableList<V>> builder =
+        new ImmutableMap.Builder<>(mapEntries.size());
+    int size = 0;
+
+    for (Entry<? extends K, ? extends Collection<? extends V>> entry : mapEntries) {
+      K key = entry.getKey();
+      Collection<? extends V> values = entry.getValue();
+      ImmutableList<V> list =
+          (valueComparator == null)
+              ? ImmutableList.copyOf(values)
+              : ImmutableList.sortedCopyOf(valueComparator, values);
+      if (!list.isEmpty()) {
+        builder.put(key, list);
+        size += list.size();
+      }
+    }
+
+    return new ImmutableListMultimap<>(builder.buildOrThrow(), size);
+  }
+
+  ImmutableListMultimap(ImmutableMap<K, ImmutableList<V>> map, int size) {
+    super(map, size);
+  }
+
+  // views
+
+  /**
+   * Returns an immutable list of the values for the given key. If no mappings in the multimap have
+   * the provided key, an empty immutable list is returned. The values are in the same order as the
+   * parameters used to build this multimap.
+   */
+  @Override
+  public ImmutableList<V> get(K key) {
+    // This cast is safe as its type is known in constructor.
+    ImmutableList<V> list = (ImmutableList<V>) map.get(key);
+    return (list == null) ? ImmutableList.<V>of() : list;
+  }
+
+  private transient ImmutableListMultimap<V, K> inverse;
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>Because an inverse of a list multimap can contain multiple pairs with the same key and
+   * value, this method returns an {@code ImmutableListMultimap} rather than the {@code
+   * ImmutableMultimap} specified in the {@code ImmutableMultimap} class.
+   *
+   */
+  @Override
+  public ImmutableListMultimap<V, K> inverse() {
+    ImmutableListMultimap<V, K> result = inverse;
+    return (result == null) ? (inverse = invert()) : result;
+  }
+
+  private ImmutableListMultimap<V, K> invert() {
+    Builder<V, K> builder = builder();
+    for (Entry<K, V> entry : entries()) {
+      builder.put(entry.getValue(), entry.getKey());
+    }
+    ImmutableListMultimap<V, K> invertedMultimap = builder.build();
+    invertedMultimap.inverse = this;
+    return invertedMultimap;
+  }
+
+  /**
+   * Guaranteed to throw an exception and leave the multimap unmodified.
+   *
+   * @throws UnsupportedOperationException always
+   */
+  @Override
+  public final ImmutableList<V> removeAll(Object key) {
+    throw new UnsupportedOperationException();
+  }
+
+  /**
+   * Guaranteed to throw an exception and leave the multimap unmodified.
+   *
+   * @throws UnsupportedOperationException always
+   */
+  @Override
+  public final ImmutableList<V> replaceValues(K key, Iterable<? extends V> values) {
+    throw new UnsupportedOperationException();
+  }
+
+  /**
+   * @serialData number of distinct keys, and then for each distinct key: the key, the number of
+   *     values for that key, and the key's values
+   */
+  private void writeObject(ObjectOutputStream stream) throws IOException {
+    stream.defaultWriteObject();
+    Serialization.writeMultimap(this, stream);
+  }
+
+  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
+    stream.defaultReadObject();
+    int keyCount = stream.readInt();
+    if (keyCount < 0) {
+      throw new InvalidObjectException("Invalid key count " + keyCount);
+    }
+    ImmutableMap.Builder<Object, ImmutableList<Object>> builder = ImmutableMap.builder();
+    int tmpSize = 0;
+
+    for (int i = 0; i < keyCount; i++) {
+      Object key = stream.readObject();
+      int valueCount = stream.readInt();
+      if (valueCount <= 0) {
+        throw new InvalidObjectException("Invalid value count " + valueCount);
+      }
+
+      ImmutableList.Builder<Object> valuesBuilder = ImmutableList.builder();
+      for (int j = 0; j < valueCount; j++) {
+        valuesBuilder.add(stream.readObject());
+      }
+      builder.put(key, valuesBuilder.build());
+      tmpSize += valueCount;
+    }
+
+    ImmutableMap<Object, ImmutableList<Object>> tmpMap;
+    try {
+      tmpMap = builder.buildOrThrow();
+    } catch (IllegalArgumentException e) {
+      throw (InvalidObjectException) new InvalidObjectException(e.getMessage()).initCause(e);
+    }
+
+    FieldSettersHolder.MAP_FIELD_SETTER.set(this, tmpMap);
+    FieldSettersHolder.SIZE_FIELD_SETTER.set(this, tmpSize);
+  }
+
+  private static final long serialVersionUID = 0;
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/ImmutableMultimap.java

@@ -0,0 +1,742 @@
+package org.xbib.datastructures.multi;
+
+import java.io.InvalidObjectException;
+import java.io.ObjectInputStream;
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Objects;
+import java.util.Set;
+import java.util.Spliterator;
+import java.util.function.BiConsumer;
+import org.xbib.datastructures.api.Multimap;
+import org.xbib.datastructures.api.SetMultimap;
+import org.xbib.datastructures.immutable.order.Ordering;
+import static java.util.Objects.requireNonNull;
+
+/**
+ * A {@link Multimap} whose contents will never change, with many other important properties
+ * detailed at {@link ImmutableCollection}.
+ *
+ * <p><b>Warning:</b> avoid <i>direct</i> usage of {@link ImmutableMultimap} as a type (as with
+ * {@link Multimap} itself). Prefer subtypes such as {@link ImmutableSetMultimap} or {@link
+ * ImmutableListMultimap}, which have well-defined {@link #equals} semantics, thus avoiding a common
+ * source of bugs and confusion.
+ *
+ * <p><b>Note:</b> every {@link ImmutableMultimap} offers an {@link #inverse} view, so there is no
+ * need for a distinct {@code ImmutableBiMultimap} type.
+ *
+ * <p><a id="iteration"></a>
+ *
+ * <p><b>Key-grouped iteration.</b> All view collections follow the same iteration order. In all
+ * current implementations, the iteration order always keeps multiple entries with the same key
+ * together. Any creation method that would customarily respect insertion order (such as {@link
+ * #copyOf(Multimap)}) instead preserves key-grouped order by inserting entries for an existing key
+ * immediately after the last entry having that key.
+ */
+public abstract class ImmutableMultimap<K, V> extends BaseImmutableMultimap<K, V>
+        implements Serializable {
+
+    /**
+     * Returns an empty multimap.
+     *
+     * <p><b>Performance note:</b> the instance returned is a singleton.
+     */
+    public static <K, V> ImmutableMultimap<K, V> of() {
+        return ImmutableListMultimap.of();
+    }
+
+    /**
+     * Returns an immutable multimap containing a single entry.
+     */
+    public static <K, V> ImmutableMultimap<K, V> of(K k1, V v1) {
+        return ImmutableListMultimap.of(k1, v1);
+    }
+
+    /**
+     * Returns an immutable multimap containing the given entries, in order.
+     */
+    public static <K, V> ImmutableMultimap<K, V> of(K k1, V v1, K k2, V v2) {
+        return ImmutableListMultimap.of(k1, v1, k2, v2);
+    }
+
+    /**
+     * Returns an immutable multimap containing the given entries, in the "key-grouped" insertion
+     * order described in the <a href="#iteration">class documentation</a>.
+     */
+    public static <K, V> ImmutableMultimap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3) {
+        return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3);
+    }
+
+    /**
+     * Returns an immutable multimap containing the given entries, in the "key-grouped" insertion
+     * order described in the <a href="#iteration">class documentation</a>.
+     */
+    public static <K, V> ImmutableMultimap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
+        return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3, k4, v4);
+    }
+
+    /**
+     * Returns an immutable multimap containing the given entries, in the "key-grouped" insertion
+     * order described in the <a href="#iteration">class documentation</a>.
+     */
+    public static <K, V> ImmutableMultimap<K, V> of(
+            K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
+        return ImmutableListMultimap.of(k1, v1, k2, v2, k3, v3, k4, v4, k5, v5);
+    }
+
+    // looking for of() with > 5 entries? Use the builder instead.
+
+    /**
+     * Returns a new builder. The generated builder is equivalent to the builder created by the {@link
+     * Builder} constructor.
+     */
+    public static <K, V> Builder<K, V> builder() {
+        return new Builder<>();
+    }
+
+    /**
+     * A builder for creating immutable multimap instances, especially {@code public static final}
+     * multimaps ("constant multimaps"). Example:
+     *
+     * <pre>{@code
+     * static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
+     *     new ImmutableMultimap.Builder<String, Integer>()
+     *         .put("one", 1)
+     *         .putAll("several", 1, 2, 3)
+     *         .putAll("many", 1, 2, 3, 4, 5)
+     *         .build();
+     * }</pre>
+     *
+     * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build
+     * multiple multimaps in series. Each multimap contains the key-value mappings in the previously
+     * created multimaps.
+     *
+     */
+    public static class Builder<K, V> {
+        final Map<K, Collection<V>> builderMap;
+        Comparator<? super K> keyComparator;
+        Comparator<? super V> valueComparator;
+
+        /**
+         * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
+         * ImmutableMultimap#builder}.
+         */
+        public Builder() {
+            this.builderMap = new LinkedHashMap<>();
+        }
+
+        Collection<V> newMutableValueCollection() {
+            return new ArrayList<>();
+        }
+
+        /**
+         * Adds a key-value mapping to the built multimap.
+         */
+        public Builder<K, V> put(K key, V value) {
+            checkEntryNotNull(key, value);
+            Collection<V> valueCollection = builderMap.get(key);
+            if (valueCollection == null) {
+                builderMap.put(key, valueCollection = newMutableValueCollection());
+            }
+            valueCollection.add(value);
+            return this;
+        }
+
+        /**
+         * Adds an entry to the built multimap.
+         */
+        public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
+            return put(entry.getKey(), entry.getValue());
+        }
+
+        /**
+         * Adds entries to the built multimap.
+         */
+        public Builder<K, V> putAll(Iterable<? extends Entry<? extends K, ? extends V>> entries) {
+            for (Entry<? extends K, ? extends V> entry : entries) {
+                put(entry);
+            }
+            return this;
+        }
+
+        /**
+         * Stores a collection of values with the same key in the built multimap.
+         *
+         * @throws NullPointerException if {@code key}, {@code values}, or any element in {@code values}
+         *                              is null. The builder is left in an invalid state.
+         */
+        public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
+            if (key == null) {
+                throw new NullPointerException("null key in entry: null=" + toString(values.iterator()));
+            }
+            Collection<V> valueCollection = builderMap.get(key);
+            if (valueCollection != null) {
+                for (V value : values) {
+                    checkEntryNotNull(key, value);
+                    valueCollection.add(value);
+                }
+                return this;
+            }
+            Iterator<? extends V> valuesItr = values.iterator();
+            if (!valuesItr.hasNext()) {
+                return this;
+            }
+            valueCollection = newMutableValueCollection();
+            while (valuesItr.hasNext()) {
+                V value = valuesItr.next();
+                checkEntryNotNull(key, value);
+                valueCollection.add(value);
+            }
+            builderMap.put(key, valueCollection);
+            return this;
+        }
+
+        /**
+         * Stores an array of values with the same key in the built multimap.
+         *
+         * @throws NullPointerException if the key or any value is null. The builder is left in an
+         *                              invalid state.
+         */
+        public Builder<K, V> putAll(K key, V... values) {
+            return putAll(key, Arrays.asList(values));
+        }
+
+        /**
+         * Stores another multimap's entries in the built multimap. The generated multimap's key and
+         * value orderings correspond to the iteration ordering of the {@code multimap.asMap()} view,
+         * with new keys and values following any existing keys and values.
+         *
+         * @throws NullPointerException if any key or value in {@code multimap} is null. The builder is
+         *                              left in an invalid state.
+         */
+        public Builder<K, V> putAll(Multimap<? extends K, ? extends V> multimap) {
+            for (Entry<? extends K, ? extends Collection<? extends V>> entry :
+                    multimap.asMap().entrySet()) {
+                putAll(entry.getKey(), entry.getValue());
+            }
+            return this;
+        }
+
+        /**
+         * Specifies the ordering of the generated multimap's keys.
+         */
+        public Builder<K, V> orderKeysBy(Comparator<? super K> keyComparator) {
+            this.keyComparator = Objects.requireNonNull(keyComparator);
+            return this;
+        }
+
+        /**
+         * Specifies the ordering of the generated multimap's values for each key.
+         */
+        public Builder<K, V> orderValuesBy(Comparator<? super V> valueComparator) {
+            this.valueComparator = Objects.requireNonNull(valueComparator);
+            return this;
+        }
+
+        Builder<K, V> combine(Builder<K, V> other) {
+            for (Entry<K, Collection<V>> entry : other.builderMap.entrySet()) {
+                putAll(entry.getKey(), entry.getValue());
+            }
+            return this;
+        }
+
+        /**
+         * Returns a newly-created immutable multimap.
+         */
+        public ImmutableMultimap<K, V> build() {
+            Collection<Entry<K, Collection<V>>> mapEntries = builderMap.entrySet();
+            if (keyComparator != null) {
+                mapEntries = Ordering.from(keyComparator).<K>onKeys().immutableSortedCopy(mapEntries);
+            }
+            return ImmutableListMultimap.fromMapEntries(mapEntries, valueComparator);
+        }
+
+
+        private static String toString(Iterator<?> iterator) {
+            StringBuilder sb = new StringBuilder().append('[');
+            boolean first = true;
+            while (iterator.hasNext()) {
+                if (!first) {
+                    sb.append(", ");
+                }
+                first = false;
+                sb.append(iterator.next());
+            }
+            return sb.append(']').toString();
+        }
+    }
+
+    /**
+     * Returns an immutable multimap containing the same mappings as {@code multimap}, in the
+     * "key-grouped" iteration order described in the class documentation.
+     *
+     * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
+     * safe to do so. The exact circumstances under which a copy will or will not be performed are
+     * undocumented and subject to change.
+     *
+     * @throws NullPointerException if any key or value in {@code multimap} is null
+     */
+    public static <K, V> ImmutableMultimap<K, V> copyOf(Multimap<? extends K, ? extends V> multimap) {
+        if (multimap instanceof ImmutableMultimap) {
+            @SuppressWarnings("unchecked") // safe since multimap is not writable
+            ImmutableMultimap<K, V> kvMultimap = (ImmutableMultimap<K, V>) multimap;
+            if (!kvMultimap.isPartialView()) {
+                return kvMultimap;
+            }
+        }
+        return ImmutableListMultimap.copyOf(multimap);
+    }
+
+    /**
+     * Returns an immutable multimap containing the specified entries. The returned multimap iterates
+     * over keys in the order they were first encountered in the input, and the values for each key
+     * are iterated in the order they were encountered.
+     *
+     * @throws NullPointerException if any key, value, or entry is null
+     */
+    public static <K, V> ImmutableMultimap<K, V> copyOf(
+            Iterable<? extends Entry<? extends K, ? extends V>> entries) {
+        return ImmutableListMultimap.copyOf(entries);
+    }
+
+    final transient ImmutableMap<K, ? extends ImmutableCollection<V>> map;
+    final transient int size;
+
+    // These constants allow the deserialization code to set final fields. This
+    // holder class makes sure they are not initialized unless an instance is
+    // deserialized.
+    static class FieldSettersHolder {
+        static final Serialization.FieldSetter<ImmutableMultimap> MAP_FIELD_SETTER =
+                Serialization.getFieldSetter(ImmutableMultimap.class, "map");
+        static final Serialization.FieldSetter<ImmutableMultimap> SIZE_FIELD_SETTER =
+                Serialization.getFieldSetter(ImmutableMultimap.class, "size");
+    }
+
+    ImmutableMultimap(ImmutableMap<K, ? extends ImmutableCollection<V>> map, int size) {
+        this.map = map;
+        this.size = size;
+    }
+
+    // mutators (not supported)
+
+    /**
+     * Guaranteed to throw an exception and leave the multimap unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    // DoNotCall wants this to be final, but we want to override it to return more specific types.
+    // Inheritance is closed, and all subtypes are @DoNotCall, so this is safe to suppress.
+    @SuppressWarnings("DoNotCall")
+    public ImmutableCollection<V> removeAll(Object key) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the multimap unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    // DoNotCall wants this to be final, but we want to override it to return more specific types.
+    // Inheritance is closed, and all subtypes are @DoNotCall, so this is safe to suppress.
+    @SuppressWarnings("DoNotCall")
+    public ImmutableCollection<V> replaceValues(K key, Iterable<? extends V> values) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the multimap unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final void clear() {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Returns an immutable collection of the values for the given key. If no mappings in the multimap
+     * have the provided key, an empty immutable collection is returned. The values are in the same
+     * order as the parameters used to build this multimap.
+     */
+    @Override
+    public abstract ImmutableCollection<V> get(K key);
+
+    /**
+     * Returns an immutable multimap which is the inverse of this one. For every key-value mapping in
+     * the original, the result will have a mapping with key and value reversed.
+     */
+    public abstract ImmutableMultimap<V, K> inverse();
+
+    /**
+     * Guaranteed to throw an exception and leave the multimap unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final boolean put(K key, V value) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the multimap unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final boolean putAll(K key, Iterable<? extends V> values) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the multimap unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final boolean putAll(Multimap<? extends K, ? extends V> multimap) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the multimap unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final boolean remove(Object key, Object value) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Returns {@code true} if this immutable multimap's implementation contains references to
+     * user-created objects that aren't accessible via this multimap's methods. This is generally used
+     * to determine whether {@code copyOf} implementations should make an explicit copy to avoid
+     * memory leaks.
+     */
+    boolean isPartialView() {
+        return map.isPartialView();
+    }
+
+    // accessors
+
+    @Override
+    public boolean containsKey(Object key) {
+        return map.containsKey(key);
+    }
+
+    @Override
+    public boolean containsValue(Object value) {
+        return value != null && super.containsValue(value);
+    }
+
+    @Override
+    public int size() {
+        return size;
+    }
+
+    // views
+
+    /**
+     * Returns an immutable set of the distinct keys in this multimap, in the same order as they
+     * appear in this multimap.
+     */
+    @Override
+    public ImmutableSet<K> keySet() {
+        return map.keySet();
+    }
+
+    @Override
+    Set<K> createKeySet() {
+        throw new AssertionError("unreachable");
+    }
+
+    /**
+     * Returns an immutable map that associates each key with its corresponding values in the
+     * multimap. Keys and values appear in the same order as in this multimap.
+     */
+    @Override
+    @SuppressWarnings("unchecked") // a widening cast
+    public ImmutableMap<K, Collection<V>> asMap() {
+        return (ImmutableMap) map;
+    }
+
+    @Override
+    Map<K, Collection<V>> createAsMap() {
+        throw new AssertionError("should never be called");
+    }
+
+    /**
+     * Returns an immutable collection of all key-value pairs in the multimap.
+     */
+    @Override
+    public ImmutableCollection<Entry<K, V>> entries() {
+        return (ImmutableCollection<Entry<K, V>>) super.entries();
+    }
+
+    @Override
+    ImmutableCollection<Entry<K, V>> createEntries() {
+        return new EntryCollection<>(this);
+    }
+
+    private static class EntryCollection<K, V> extends ImmutableCollection<Entry<K, V>> {
+        final ImmutableMultimap<K, V> multimap;
+
+        EntryCollection(ImmutableMultimap<K, V> multimap) {
+            this.multimap = multimap;
+        }
+
+        @Override
+        public UnmodifiableIterator<Entry<K, V>> iterator() {
+            return multimap.entryIterator();
+        }
+
+        @Override
+        boolean isPartialView() {
+            return multimap.isPartialView();
+        }
+
+        @Override
+        public int size() {
+            return multimap.size();
+        }
+
+        @Override
+        public boolean contains(Object object) {
+            if (object instanceof Entry<?, ?> entry) {
+                return multimap.containsEntry(entry.getKey(), entry.getValue());
+            }
+            return false;
+        }
+
+        private static final long serialVersionUID = 0;
+    }
+
+    @Override
+    UnmodifiableIterator<Entry<K, V>> entryIterator() {
+        return new UnmodifiableIterator<Entry<K, V>>() {
+            final Iterator<? extends Entry<K, ? extends ImmutableCollection<V>>> asMapItr =
+                    map.entrySet().iterator();
+            K currentKey = null;
+            Iterator<V> valueItr = emptyIterator();
+
+            @Override
+            public boolean hasNext() {
+                return valueItr.hasNext() || asMapItr.hasNext();
+            }
+
+            @Override
+            public Entry<K, V> next() {
+                if (!valueItr.hasNext()) {
+                    Entry<K, ? extends ImmutableCollection<V>> entry = asMapItr.next();
+                    currentKey = entry.getKey();
+                    valueItr = entry.getValue().iterator();
+                }
+                /*
+                 * requireNonNull is safe: The first call to this method always enters the !hasNext() case
+                 * and populates currentKey, after which it's never cleared.
+                 */
+                return new ImmutableEntry<>(requireNonNull(currentKey), valueItr.next());
+            }
+        };
+    }
+
+    @Override
+    Spliterator<Entry<K, V>> entrySpliterator() {
+        return CollectSpliterators.flatMap(
+                asMap().entrySet().spliterator(),
+                keyToValueCollectionEntry -> {
+                    K key = keyToValueCollectionEntry.getKey();
+                    Collection<V> valueCollection = keyToValueCollectionEntry.getValue();
+                    return CollectSpliterators.map(
+                            valueCollection.spliterator(), (V value) -> Maps.immutableEntry(key, value));
+                },
+                Spliterator.SIZED | (this instanceof SetMultimap ? Spliterator.DISTINCT : 0),
+                size());
+    }
+
+    @Override
+    public void forEach(BiConsumer<? super K, ? super V> action) {
+        Objects.requireNonNull(action);
+        asMap()
+                .forEach(
+                        (key, valueCollection) -> valueCollection.forEach(value -> action.accept(key, value)));
+    }
+
+    /**
+     * Returns an immutable multiset containing all the keys in this multimap, in the same order and
+     * with the same frequencies as they appear in this multimap; to get only a single occurrence of
+     * each key, use {@link #keySet}.
+     */
+    @Override
+    public ImmutableMultiset<K> keys() {
+        return (ImmutableMultiset<K>) super.keys();
+    }
+
+    @Override
+    ImmutableMultiset<K> createKeys() {
+        return new Keys();
+    }
+
+    @SuppressWarnings("serial") // Uses writeReplace, not default serialization
+    class Keys extends ImmutableMultiset<K> {
+        @Override
+        public boolean contains(Object object) {
+            return containsKey(object);
+        }
+
+        @Override
+        public int count(Object element) {
+            Collection<V> values = map.get(element);
+            return (values == null) ? 0 : values.size();
+        }
+
+        @Override
+        public ImmutableSet<K> elementSet() {
+            return keySet();
+        }
+
+        @Override
+        public int size() {
+            return ImmutableMultimap.this.size();
+        }
+
+        @Override
+        ImmutableMultiset.Entry<K> getEntry(int index) {
+            Entry<K, ? extends Collection<V>> entry = map.entrySet().asList().get(index);
+            return Multisets.immutableEntry(entry.getKey(), entry.getValue().size());
+        }
+
+        @Override
+        boolean isPartialView() {
+            return true;
+        }
+
+        @Override
+        Object writeReplace() {
+            return new KeysSerializedForm(ImmutableMultimap.this);
+        }
+
+        private void readObject(ObjectInputStream stream) throws InvalidObjectException {
+            throw new InvalidObjectException("Use KeysSerializedForm");
+        }
+    }
+
+    private static final class KeysSerializedForm implements Serializable {
+        final ImmutableMultimap<?, ?> multimap;
+
+        KeysSerializedForm(ImmutableMultimap<?, ?> multimap) {
+            this.multimap = multimap;
+        }
+
+        Object readResolve() {
+            return multimap.keys();
+        }
+    }
+
+    /**
+     * Returns an immutable collection of the values in this multimap. Its iterator traverses the
+     * values for the first key, the values for the second key, and so on.
+     */
+    @Override
+    public ImmutableCollection<V> values() {
+        return (ImmutableCollection<V>) super.values();
+    }
+
+    @Override
+    ImmutableCollection<V> createValues() {
+        return new Values<>(this);
+    }
+
+    @Override
+    UnmodifiableIterator<V> valueIterator() {
+        return new UnmodifiableIterator<V>() {
+            final Iterator<? extends ImmutableCollection<V>> valueCollectionItr = map.values().iterator();
+            Iterator<V> valueItr = Iterators.emptyIterator();
+
+            @Override
+            public boolean hasNext() {
+                return valueItr.hasNext() || valueCollectionItr.hasNext();
+            }
+
+            @Override
+            public V next() {
+                if (!valueItr.hasNext()) {
+                    valueItr = valueCollectionItr.next().iterator();
+                }
+                return valueItr.next();
+            }
+        };
+    }
+
+    private static final class Values<K, V> extends ImmutableCollection<V> {
+        private final transient ImmutableMultimap<K, V> multimap;
+
+        Values(ImmutableMultimap<K, V> multimap) {
+            this.multimap = multimap;
+        }
+
+        @Override
+        public boolean contains(Object object) {
+            return multimap.containsValue(object);
+        }
+
+        @Override
+        public UnmodifiableIterator<V> iterator() {
+            return multimap.valueIterator();
+        }
+
+        @Override
+        int copyIntoArray(Object[] dst, int offset) {
+            for (ImmutableCollection<V> valueCollection : multimap.map.values()) {
+                offset = valueCollection.copyIntoArray(dst, offset);
+            }
+            return offset;
+        }
+
+        @Override
+        public int size() {
+            return multimap.size();
+        }
+
+        @Override
+        boolean isPartialView() {
+            return true;
+        }
+
+        private static final long serialVersionUID = 0;
+    }
+
+    private static final long serialVersionUID = 0;
+
+    private static void checkEntryNotNull(Object key, Object value) {
+        if (key == null) {
+            throw new NullPointerException("null key in entry: null=" + value);
+        } else if (value == null) {
+            throw new NullPointerException("null value in entry: " + key + "=null");
+        }
+    }
+
+    private static <T extends Object> UnmodifiableIterator<T> emptyIterator() {
+        return emptyListIterator();
+    }
+
+    /**
+     * Returns the empty iterator.
+     *
+     * <p>The {@link Iterable} equivalent of this method is {@link ImmutableSet#of()}.
+     */
+    // Casting to any type is safe since there are no actual elements.
+    @SuppressWarnings("unchecked")
+    static <T extends Object> UnmodifiableListIterator<T> emptyListIterator() {
+        return (UnmodifiableListIterator<T>) ImmutableCollection.ArrayItr.EMPTY;
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/ImmutableMultiset.java

@@ -0,0 +1,592 @@
+package org.xbib.datastructures.multi;
+
+import java.io.InvalidObjectException;
+import java.io.ObjectInputStream;
+import java.io.Serializable;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Objects;
+import java.util.function.Function;
+import java.util.function.ToIntFunction;
+import java.util.stream.Collector;
+import org.xbib.datastructures.api.Multiset;
+import static java.util.Objects.requireNonNull;
+
+/**
+ * A {@link Multiset} whose contents will never change, with many other important properties
+ * detailed at {@link ImmutableCollection}.
+ *
+ * <p><b>Grouped iteration.</b> In all current implementations, duplicate elements always appear
+ * consecutively when iterating. Elements iterate in order by the <i>first</i> appearance of that
+ * element when the multiset was created.
+ *
+ */
+@SuppressWarnings("serial") // we're overriding default serialization
+public abstract class ImmutableMultiset<E> extends ImmutableCollection<E>
+        implements Multiset<E> {
+
+    /**
+     * Returns a {@code Collector} that accumulates the input elements into a new {@code
+     * ImmutableMultiset}. Elements iterate in order by the <i>first</i> appearance of that element in
+     * encounter order.
+     *
+     * @since 21.0
+     */
+    public static <E> Collector<E, ?, ImmutableMultiset<E>> toImmutableMultiset() {
+        return CollectCollectors.toImmutableMultiset(Function.identity(), e -> 1);
+    }
+
+    /**
+     * Returns a {@code Collector} that accumulates elements into an {@code ImmutableMultiset} whose
+     * elements are the result of applying {@code elementFunction} to the inputs, with counts equal to
+     * the result of applying {@code countFunction} to the inputs.
+     *
+     * <p>If the mapped elements contain duplicates (according to {@link Object#equals}), the first
+     * occurrence in encounter order appears in the resulting multiset, with count equal to the sum of
+     * the outputs of {@code countFunction.applyAsInt(t)} for each {@code t} mapped to that element.
+     *
+     * @since 22.0
+     */
+    public static <T extends Object, E>
+    Collector<T, ?, ImmutableMultiset<E>> toImmutableMultiset(
+            Function<? super T, ? extends E> elementFunction,
+            ToIntFunction<? super T> countFunction) {
+        return CollectCollectors.toImmutableMultiset(elementFunction, countFunction);
+    }
+
+    /**
+     * Returns the empty immutable multiset.
+     *
+     * <p><b>Performance note:</b> the instance returned is a singleton.
+     */
+    @SuppressWarnings("unchecked") // all supported methods are covariant
+    public static <E> ImmutableMultiset<E> of() {
+        return (ImmutableMultiset<E>) RegularImmutableMultiset.EMPTY;
+    }
+
+    /**
+     * Returns an immutable multiset containing a single element.
+     *
+     * @throws NullPointerException if {@code element} is null
+     * @since 6.0 (source-compatible since 2.0)
+     */
+    public static <E> ImmutableMultiset<E> of(E element) {
+        return copyFromElements(element);
+    }
+
+    /**
+     * Returns an immutable multiset containing the given elements, in order.
+     *
+     * @throws NullPointerException if any element is null
+     * @since 6.0 (source-compatible since 2.0)
+     */
+    public static <E> ImmutableMultiset<E> of(E e1, E e2) {
+        return copyFromElements(e1, e2);
+    }
+
+    /**
+     * Returns an immutable multiset containing the given elements, in the "grouped iteration order"
+     * described in the class documentation.
+     *
+     * @throws NullPointerException if any element is null
+     * @since 6.0 (source-compatible since 2.0)
+     */
+    public static <E> ImmutableMultiset<E> of(E e1, E e2, E e3) {
+        return copyFromElements(e1, e2, e3);
+    }
+
+    /**
+     * Returns an immutable multiset containing the given elements, in the "grouped iteration order"
+     * described in the class documentation.
+     *
+     * @throws NullPointerException if any element is null
+     * @since 6.0 (source-compatible since 2.0)
+     */
+    public static <E> ImmutableMultiset<E> of(E e1, E e2, E e3, E e4) {
+        return copyFromElements(e1, e2, e3, e4);
+    }
+
+    /**
+     * Returns an immutable multiset containing the given elements, in the "grouped iteration order"
+     * described in the class documentation.
+     *
+     * @throws NullPointerException if any element is null
+     * @since 6.0 (source-compatible since 2.0)
+     */
+    public static <E> ImmutableMultiset<E> of(E e1, E e2, E e3, E e4, E e5) {
+        return copyFromElements(e1, e2, e3, e4, e5);
+    }
+
+    /**
+     * Returns an immutable multiset containing the given elements, in the "grouped iteration order"
+     * described in the class documentation.
+     *
+     * @throws NullPointerException if any element is null
+     * @since 6.0 (source-compatible since 2.0)
+     */
+    public static <E> ImmutableMultiset<E> of(E e1, E e2, E e3, E e4, E e5, E e6, E... others) {
+        return new Builder<E>().add(e1).add(e2).add(e3).add(e4).add(e5).add(e6).add(others).build();
+    }
+
+    /**
+     * Returns an immutable multiset containing the given elements, in the "grouped iteration order"
+     * described in the class documentation.
+     *
+     * @throws NullPointerException if any of {@code elements} is null
+     * @since 6.0
+     */
+    public static <E> ImmutableMultiset<E> copyOf(E[] elements) {
+        return copyFromElements(elements);
+    }
+
+    /**
+     * Returns an immutable multiset containing the given elements, in the "grouped iteration order"
+     * described in the class documentation.
+     *
+     * @throws NullPointerException if any of {@code elements} is null
+     */
+    public static <E> ImmutableMultiset<E> copyOf(Iterable<? extends E> elements) {
+        if (elements instanceof ImmutableMultiset) {
+            @SuppressWarnings("unchecked") // all supported methods are covariant
+            ImmutableMultiset<E> result = (ImmutableMultiset<E>) elements;
+            if (!result.isPartialView()) {
+                return result;
+            }
+        }
+
+        Multiset<? extends E> multiset =
+                (elements instanceof Multiset)
+                        ? Multisets.cast(elements)
+                        : LinkedHashMultiset.create(elements);
+
+        return copyFromEntries(multiset.entrySet());
+    }
+
+    /**
+     * Returns an immutable multiset containing the given elements, in the "grouped iteration order"
+     * described in the class documentation.
+     *
+     * @throws NullPointerException if any of {@code elements} is null
+     */
+    public static <E> ImmutableMultiset<E> copyOf(Iterator<? extends E> elements) {
+        Multiset<E> multiset = LinkedHashMultiset.create();
+        Iterators.addAll(multiset, elements);
+        return copyFromEntries(multiset.entrySet());
+    }
+
+    private static <E> ImmutableMultiset<E> copyFromElements(E... elements) {
+        Multiset<E> multiset = LinkedHashMultiset.create();
+        Collections.addAll(multiset, elements);
+        return copyFromEntries(multiset.entrySet());
+    }
+
+    static <E> ImmutableMultiset<E> copyFromEntries(
+            Collection<? extends Entry<? extends E>> entries) {
+        if (entries.isEmpty()) {
+            return of();
+        } else {
+            return RegularImmutableMultiset.create(entries);
+        }
+    }
+
+    ImmutableMultiset() {}
+
+    @Override
+    public UnmodifiableIterator<E> iterator() {
+        final Iterator<Entry<E>> entryIterator = entrySet().iterator();
+        return new UnmodifiableIterator<E>() {
+            int remaining;
+            E element;
+
+            @Override
+            public boolean hasNext() {
+                return (remaining > 0) || entryIterator.hasNext();
+            }
+
+            @Override
+            public E next() {
+                if (remaining <= 0) {
+                    Entry<E> entry = entryIterator.next();
+                    element = entry.getElement();
+                    remaining = entry.getCount();
+                }
+                remaining--;
+                /*
+                 * requireNonNull is safe because `remaining` starts at 0, forcing us to initialize
+                 * `element` above. After that, we never clear it.
+                 */
+                return requireNonNull(element);
+            }
+        };
+    }
+
+    private transient ImmutableList<E> asList;
+
+    @Override
+    public ImmutableList<E> asList() {
+        ImmutableList<E> result = asList;
+        return (result == null) ? asList = super.asList() : result;
+    }
+
+    @Override
+    public boolean contains(Object object) {
+        return count(object) > 0;
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the collection unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final int add(E element, int occurrences) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the collection unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final int remove(Object element, int occurrences) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the collection unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final int setCount(E element, int count) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the collection unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final boolean setCount(E element, int oldCount, int newCount) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    int copyIntoArray(Object[] dst, int offset) {
+        for (Multiset.Entry<E> entry : entrySet()) {
+            Arrays.fill(dst, offset, offset + entry.getCount(), entry.getElement());
+            offset += entry.getCount();
+        }
+        return offset;
+    }
+
+    @Override
+    public boolean equals(Object object) {
+        return Multisets.equalsImpl(this, object);
+    }
+
+    @Override
+    public int hashCode() {
+        return Sets.hashCodeImpl(entrySet());
+    }
+
+    @Override
+    public String toString() {
+        return entrySet().toString();
+    }
+
+    @Override
+    public abstract ImmutableSet<E> elementSet();
+
+    private transient ImmutableSet<Entry<E>> entrySet;
+
+    @Override
+    public ImmutableSet<Entry<E>> entrySet() {
+        ImmutableSet<Entry<E>> es = entrySet;
+        return (es == null) ? (entrySet = createEntrySet()) : es;
+    }
+
+    private ImmutableSet<Entry<E>> createEntrySet() {
+        return isEmpty() ? ImmutableSet.<Entry<E>>of() : new EntrySet();
+    }
+
+    abstract Entry<E> getEntry(int index);
+
+    private final class EntrySet extends IndexedImmutableSet<Entry<E>> {
+        @Override
+        boolean isPartialView() {
+            return ImmutableMultiset.this.isPartialView();
+        }
+
+        @Override
+        Entry<E> get(int index) {
+            return getEntry(index);
+        }
+
+        @Override
+        public int size() {
+            return elementSet().size();
+        }
+
+        @Override
+        public boolean contains(Object o) {
+            if (o instanceof Entry) {
+                Entry<?> entry = (Entry<?>) o;
+                if (entry.getCount() <= 0) {
+                    return false;
+                }
+                int count = count(entry.getElement());
+                return count == entry.getCount();
+            }
+            return false;
+        }
+
+        @Override
+        public int hashCode() {
+            return ImmutableMultiset.this.hashCode();
+        }
+
+        @Override
+        Object writeReplace() {
+            return new EntrySetSerializedForm<E>(ImmutableMultiset.this);
+        }
+
+        private void readObject(ObjectInputStream stream) throws InvalidObjectException {
+            throw new InvalidObjectException("Use EntrySetSerializedForm");
+        }
+
+        private static final long serialVersionUID = 0;
+    }
+
+    static class EntrySetSerializedForm<E> implements Serializable {
+        final ImmutableMultiset<E> multiset;
+
+        EntrySetSerializedForm(ImmutableMultiset<E> multiset) {
+            this.multiset = multiset;
+        }
+
+        Object readResolve() {
+            return multiset.entrySet();
+        }
+    }
+
+    @Override
+    Object writeReplace() {
+        return new SerializedForm(this);
+    }
+
+    private void readObject(ObjectInputStream stream) throws InvalidObjectException {
+        throw new InvalidObjectException("Use SerializedForm");
+    }
+
+    /**
+     * Returns a new builder. The generated builder is equivalent to the builder created by the {@link
+     * Builder} constructor.
+     */
+    public static <E> Builder<E> builder() {
+        return new Builder<E>();
+    }
+
+    /**
+     * A builder for creating immutable multiset instances, especially {@code public static final}
+     * multisets ("constant multisets"). Example:
+     *
+     * <pre>{@code
+     * public static final ImmutableMultiset<Bean> BEANS =
+     *     new ImmutableMultiset.Builder<Bean>()
+     *         .addCopies(Bean.COCOA, 4)
+     *         .addCopies(Bean.GARDEN, 6)
+     *         .addCopies(Bean.RED, 8)
+     *         .addCopies(Bean.BLACK_EYED, 10)
+     *         .build();
+     * }</pre>
+     *
+     * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build
+     * multiple multisets in series.
+     *
+     * @since 2.0
+     */
+    public static class Builder<E> extends ImmutableCollection.Builder<E> {
+        final Multiset<E> contents;
+
+        /**
+         * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
+         * ImmutableMultiset#builder}.
+         */
+        public Builder() {
+            this(LinkedHashMultiset.<E>create());
+        }
+
+        Builder(Multiset<E> contents) {
+            this.contents = contents;
+        }
+
+        /**
+         * Adds {@code element} to the {@code ImmutableMultiset}.
+         *
+         * @param element the element to add
+         * @return this {@code Builder} object
+         * @throws NullPointerException if {@code element} is null
+         */
+        @Override
+        public Builder<E> add(E element) {
+            contents.add(Objects.requireNonNull(element));
+            return this;
+        }
+
+        /**
+         * Adds each element of {@code elements} to the {@code ImmutableMultiset}.
+         *
+         * @param elements the elements to add
+         * @return this {@code Builder} object
+         * @throws NullPointerException if {@code elements} is null or contains a null element
+         */
+        @Override
+        public Builder<E> add(E... elements) {
+            super.add(elements);
+            return this;
+        }
+
+        /**
+         * Adds a number of occurrences of an element to this {@code ImmutableMultiset}.
+         *
+         * @param element the element to add
+         * @param occurrences the number of occurrences of the element to add. May be zero, in which
+         *     case no change will be made.
+         * @return this {@code Builder} object
+         * @throws NullPointerException if {@code element} is null
+         * @throws IllegalArgumentException if {@code occurrences} is negative, or if this operation
+         *     would result in more than {@link Integer#MAX_VALUE} occurrences of the element
+         */
+        public Builder<E> addCopies(E element, int occurrences) {
+            contents.add(Objects.requireNonNull(element), occurrences);
+            return this;
+        }
+
+        /**
+         * Adds or removes the necessary occurrences of an element such that the element attains the
+         * desired count.
+         *
+         * @param element the element to add or remove occurrences of
+         * @param count the desired count of the element in this multiset
+         * @return this {@code Builder} object
+         * @throws NullPointerException if {@code element} is null
+         * @throws IllegalArgumentException if {@code count} is negative
+         */
+        public Builder<E> setCount(E element, int count) {
+            contents.setCount(Objects.requireNonNull(element), count);
+            return this;
+        }
+
+        /**
+         * Adds each element of {@code elements} to the {@code ImmutableMultiset}.
+         *
+         * @param elements the {@code Iterable} to add to the {@code ImmutableMultiset}
+         * @return this {@code Builder} object
+         * @throws NullPointerException if {@code elements} is null or contains a null element
+         */
+        @Override
+        public Builder<E> addAll(Iterable<? extends E> elements) {
+            if (elements instanceof Multiset) {
+                Multiset<? extends E> multiset = Multisets.cast(elements);
+                multiset.forEachEntry((e, n) -> contents.add(Objects.requireNonNull(e), n));
+            } else {
+                super.addAll(elements);
+            }
+            return this;
+        }
+
+        /**
+         * Adds each element of {@code elements} to the {@code ImmutableMultiset}.
+         *
+         * @param elements the elements to add to the {@code ImmutableMultiset}
+         * @return this {@code Builder} object
+         * @throws NullPointerException if {@code elements} is null or contains a null element
+         */
+        @Override
+        public Builder<E> addAll(Iterator<? extends E> elements) {
+            super.addAll(elements);
+            return this;
+        }
+
+        /**
+         * Returns a newly-created {@code ImmutableMultiset} based on the contents of the {@code
+         * Builder}.
+         */
+        @Override
+        public ImmutableMultiset<E> build() {
+            return copyOf(contents);
+        }
+
+        ImmutableMultiset<E> buildJdkBacked() {
+            if (contents.isEmpty()) {
+                return of();
+            }
+            return JdkBackedImmutableMultiset.create(contents.entrySet());
+        }
+    }
+
+    static final class ElementSet<E> extends ImmutableSet.Indexed<E> {
+        private final List<Entry<E>> entries;
+        // TODO(cpovirk): @Weak?
+        private final Multiset<E> delegate;
+
+        ElementSet(List<Entry<E>> entries, Multiset<E> delegate) {
+            this.entries = entries;
+            this.delegate = delegate;
+        }
+
+        @Override
+        E get(int index) {
+            return entries.get(index).getElement();
+        }
+
+        @Override
+        public boolean contains(Object object) {
+            return delegate.contains(object);
+        }
+
+        @Override
+        boolean isPartialView() {
+            return true;
+        }
+
+        @Override
+        public int size() {
+            return entries.size();
+        }
+    }
+
+    static final class SerializedForm implements Serializable {
+        final Object[] elements;
+        final int[] counts;
+
+        // "extends Object" works around https://github.com/typetools/checker-framework/issues/3013
+        SerializedForm(Multiset<? extends Object> multiset) {
+            int distinct = multiset.entrySet().size();
+            elements = new Object[distinct];
+            counts = new int[distinct];
+            int i = 0;
+            for (Entry<? extends Object> entry : multiset.entrySet()) {
+                elements[i] = entry.getElement();
+                counts[i] = entry.getCount();
+                i++;
+            }
+        }
+
+        Object readResolve() {
+            LinkedHashMultiset<Object> multiset = LinkedHashMultiset.create(elements.length);
+            for (int i = 0; i < elements.length; i++) {
+                multiset.add(elements[i], counts[i]);
+            }
+            return ImmutableMultiset.copyOf(multiset);
+        }
+
+        private static final long serialVersionUID = 0;
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/ImmutableSetMultimap.java

@@ -0,0 +1,619 @@
+package org.xbib.datastructures.multi;
+
+//import com.google.common.base.MoreObjects;
+
+import java.io.IOException;
+import java.io.InvalidObjectException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Map.Entry;
+import java.util.Objects;
+import java.util.function.Function;
+import java.util.function.Supplier;
+import java.util.stream.Collector;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import org.xbib.datastructures.api.Multimap;
+import org.xbib.datastructures.api.SetMultimap;
+import org.xbib.datastructures.immutable.order.Ordering;
+
+/**
+ * A {@link SetMultimap} whose contents will never change, with many other important properties
+ * detailed at {@link ImmutableCollection}.
+ *
+ * <p><b>Warning:</b> As in all {@link SetMultimap}s, do not modify either a key <i>or a value</i>
+ * of a {@code ImmutableSetMultimap} in a way that affects its {@link Object#equals} behavior.
+ * Undefined behavior and bugs will result.
+ *
+ * <p>See the Guava User Guide article on <a href=
+ * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
+ */
+public class ImmutableSetMultimap<K, V> extends ImmutableMultimap<K, V>
+        implements SetMultimap<K, V> {
+    /**
+     * Returns a {@link Collector} that accumulates elements into an {@code ImmutableSetMultimap}
+     * whose keys and values are the result of applying the provided mapping functions to the input
+     * elements.
+     *
+     * <p>For streams with defined encounter order (as defined in the Ordering section of the {@link
+     * java.util.stream} Javadoc), that order is preserved, but entries are <a
+     * href="ImmutableMultimap.html#iteration">grouped by key</a>.
+     *
+     * <p>Example:
+     *
+     * <pre>{@code
+     * static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
+     *     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
+     *         .collect(toImmutableSetMultimap(str -> str.charAt(0), str -> str.substring(1)));
+     *
+     * // is equivalent to
+     *
+     * static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
+     *     new ImmutableSetMultimap.Builder<Character, String>()
+     *         .put('b', "anana")
+     *         .putAll('a', "pple", "sparagus")
+     *         .putAll('c', "arrot", "herry")
+     *         .build();
+     * }</pre>
+     */
+    public static <T extends Object, K, V>
+    Collector<T, ?, ImmutableSetMultimap<K, V>> toImmutableSetMultimap(
+            Function<? super T, ? extends K> keyFunction,
+            Function<? super T, ? extends V> valueFunction) {
+        Objects.requireNonNull(keyFunction, "keyFunction");
+        Objects.requireNonNull(valueFunction, "valueFunction");
+        return Collector.of(
+                ImmutableSetMultimap::<K, V>builder,
+                (builder, t) -> builder.put(keyFunction.apply(t), valueFunction.apply(t)),
+                Builder::combine,
+                Builder::build);
+    }
+
+    /**
+     * Returns a {@code Collector} accumulating entries into an {@code ImmutableSetMultimap}. Each
+     * input element is mapped to a key and a stream of values, each of which are put into the
+     * resulting {@code Multimap}, in the encounter order of the stream and the encounter order of the
+     * streams of values.
+     *
+     * <p>Example:
+     *
+     * <pre>{@code
+     * static final ImmutableSetMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
+     *     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
+     *         .collect(
+     *             flatteningToImmutableSetMultimap(
+     *                  str -> str.charAt(0),
+     *                  str -> str.substring(1).chars().mapToObj(c -> (char) c));
+     *
+     * // is equivalent to
+     *
+     * static final ImmutableSetMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
+     *     ImmutableSetMultimap.<Character, Character>builder()
+     *         .putAll('b', Arrays.asList('a', 'n', 'a', 'n', 'a'))
+     *         .putAll('a', Arrays.asList('p', 'p', 'l', 'e'))
+     *         .putAll('c', Arrays.asList('a', 'r', 'r', 'o', 't'))
+     *         .putAll('a', Arrays.asList('s', 'p', 'a', 'r', 'a', 'g', 'u', 's'))
+     *         .putAll('c', Arrays.asList('h', 'e', 'r', 'r', 'y'))
+     *         .build();
+     *
+     * // after deduplication, the resulting multimap is equivalent to
+     *
+     * static final ImmutableSetMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
+     *     ImmutableSetMultimap.<Character, Character>builder()
+     *         .putAll('b', Arrays.asList('a', 'n'))
+     *         .putAll('a', Arrays.asList('p', 'l', 'e', 's', 'a', 'r', 'g', 'u'))
+     *         .putAll('c', Arrays.asList('a', 'r', 'o', 't', 'h', 'e', 'y'))
+     *         .build();
+     * }
+     * }</pre>
+     *
+     */
+    public static <T extends Object, K, V>
+    Collector<T, ?, ImmutableSetMultimap<K, V>> flatteningToImmutableSetMultimap(
+            Function<? super T, ? extends K> keyFunction,
+            Function<? super T, ? extends Stream<? extends V>> valuesFunction) {
+        Objects.requireNonNull(keyFunction);
+        Objects.requireNonNull(valuesFunction);
+        return Collectors.collectingAndThen(
+                flatteningToMultimap(
+                        input -> Objects.requireNonNull(keyFunction.apply(input)),
+                        input -> valuesFunction.apply(input).peek(Objects::requireNonNull),
+                        MultimapBuilder.linkedHashKeys().linkedHashSetValues()::<K, V>build),
+                ImmutableSetMultimap::copyOf);
+    }
+
+    private static <
+            T extends Object,
+            K extends Object,
+            V extends Object,
+            M extends Multimap<K, V>>
+    Collector<T, ?, M> flatteningToMultimap(
+            Function<? super T, ? extends K> keyFunction,
+            Function<? super T, ? extends Stream<? extends V>> valueFunction,
+            Supplier<M> multimapSupplier) {
+        Objects.requireNonNull(keyFunction);
+        Objects.requireNonNull(valueFunction);
+        Objects.requireNonNull(multimapSupplier);
+        return Collector.of(
+                multimapSupplier,
+                (multimap, input) -> {
+                    K key = keyFunction.apply(input);
+                    Collection<V> valuesForKey = multimap.get(key);
+                    valueFunction.apply(input).forEachOrdered(valuesForKey::add);
+                },
+                (multimap1, multimap2) -> {
+                    multimap1.putAll(multimap2);
+                    return multimap1;
+                });
+    }
+
+    /**
+     * Returns the empty multimap.
+     *
+     * <p><b>Performance note:</b> the instance returned is a singleton.
+     */
+    // Casting is safe because the multimap will never hold any elements.
+    @SuppressWarnings("unchecked")
+    public static <K, V> ImmutableSetMultimap<K, V> of() {
+        return (ImmutableSetMultimap<K, V>) EmptyImmutableSetMultimap.INSTANCE;
+    }
+
+    /**
+     * Returns an immutable multimap containing a single entry.
+     */
+    public static <K, V> ImmutableSetMultimap<K, V> of(K k1, V v1) {
+        Builder<K, V> builder = ImmutableSetMultimap.builder();
+        builder.put(k1, v1);
+        return builder.build();
+    }
+
+    /**
+     * Returns an immutable multimap containing the given entries, in order. Repeated occurrences of
+     * an entry (according to {@link Object#equals}) after the first are ignored.
+     */
+    public static <K, V> ImmutableSetMultimap<K, V> of(K k1, V v1, K k2, V v2) {
+        Builder<K, V> builder = ImmutableSetMultimap.builder();
+        builder.put(k1, v1);
+        builder.put(k2, v2);
+        return builder.build();
+    }
+
+    /**
+     * Returns an immutable multimap containing the given entries, in order. Repeated occurrences of
+     * an entry (according to {@link Object#equals}) after the first are ignored.
+     */
+    public static <K, V> ImmutableSetMultimap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3) {
+        Builder<K, V> builder = ImmutableSetMultimap.builder();
+        builder.put(k1, v1);
+        builder.put(k2, v2);
+        builder.put(k3, v3);
+        return builder.build();
+    }
+
+    /**
+     * Returns an immutable multimap containing the given entries, in order. Repeated occurrences of
+     * an entry (according to {@link Object#equals}) after the first are ignored.
+     */
+    public static <K, V> ImmutableSetMultimap<K, V> of(
+            K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4) {
+        Builder<K, V> builder = ImmutableSetMultimap.builder();
+        builder.put(k1, v1);
+        builder.put(k2, v2);
+        builder.put(k3, v3);
+        builder.put(k4, v4);
+        return builder.build();
+    }
+
+    /**
+     * Returns an immutable multimap containing the given entries, in order. Repeated occurrences of
+     * an entry (according to {@link Object#equals}) after the first are ignored.
+     */
+    public static <K, V> ImmutableSetMultimap<K, V> of(
+            K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5) {
+        Builder<K, V> builder = ImmutableSetMultimap.builder();
+        builder.put(k1, v1);
+        builder.put(k2, v2);
+        builder.put(k3, v3);
+        builder.put(k4, v4);
+        builder.put(k5, v5);
+        return builder.build();
+    }
+
+    // looking for of() with > 5 entries? Use the builder instead.
+
+    /**
+     * Returns a new {@link Builder}.
+     */
+    public static <K, V> Builder<K, V> builder() {
+        return new Builder<>();
+    }
+
+    /**
+     * A builder for creating immutable {@code SetMultimap} instances, especially {@code public static
+     * final} multimaps ("constant multimaps"). Example:
+     *
+     * <pre>{@code
+     * static final Multimap<String, Integer> STRING_TO_INTEGER_MULTIMAP =
+     *     new ImmutableSetMultimap.Builder<String, Integer>()
+     *         .put("one", 1)
+     *         .putAll("several", 1, 2, 3)
+     *         .putAll("many", 1, 2, 3, 4, 5)
+     *         .build();
+     * }</pre>
+     *
+     * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build
+     * multiple multimaps in series. Each multimap contains the key-value mappings in the previously
+     * created multimaps.
+     *
+     * @since 2.0
+     */
+    public static final class Builder<K, V> extends ImmutableMultimap.Builder<K, V> {
+        /**
+         * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
+         * ImmutableSetMultimap#builder}.
+         */
+        public Builder() {
+            super();
+        }
+
+        @Override
+        Collection<V> newMutableValueCollection() {
+            return Platform.preservesInsertionOrderOnAddsSet();
+        }
+
+        /**
+         * Adds a key-value mapping to the built multimap if it is not already present.
+         */
+        @Override
+        public Builder<K, V> put(K key, V value) {
+            super.put(key, value);
+            return this;
+        }
+
+        /**
+         * Adds an entry to the built multimap if it is not already present.
+         */
+        @Override
+        public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
+            super.put(entry);
+            return this;
+        }
+
+        @Override
+        public Builder<K, V> putAll(Iterable<? extends Entry<? extends K, ? extends V>> entries) {
+            super.putAll(entries);
+            return this;
+        }
+
+        @Override
+        public Builder<K, V> putAll(K key, Iterable<? extends V> values) {
+            super.putAll(key, values);
+            return this;
+        }
+
+        @Override
+        public Builder<K, V> putAll(K key, V... values) {
+            return putAll(key, Arrays.asList(values));
+        }
+
+        @Override
+        public Builder<K, V> putAll(Multimap<? extends K, ? extends V> multimap) {
+            for (Entry<? extends K, ? extends Collection<? extends V>> entry :
+                    multimap.asMap().entrySet()) {
+                putAll(entry.getKey(), entry.getValue());
+            }
+            return this;
+        }
+
+        @Override
+        Builder<K, V> combine(ImmutableMultimap.Builder<K, V> other) {
+            super.combine(other);
+            return this;
+        }
+
+        @Override
+        public Builder<K, V> orderKeysBy(Comparator<? super K> keyComparator) {
+            super.orderKeysBy(keyComparator);
+            return this;
+        }
+
+        /**
+         * Specifies the ordering of the generated multimap's values for each key.
+         *
+         * <p>If this method is called, the sets returned by the {@code get()} method of the generated
+         * multimap and its {@link Multimap#asMap()} view are {@link ImmutableSortedSet} instances.
+         * However, serialization does not preserve that property, though it does maintain the key and
+         * value ordering.
+         */
+        @Override
+        public Builder<K, V> orderValuesBy(Comparator<? super V> valueComparator) {
+            super.orderValuesBy(valueComparator);
+            return this;
+        }
+
+        /**
+         * Returns a newly-created immutable set multimap.
+         */
+        @Override
+        public ImmutableSetMultimap<K, V> build() {
+            Collection<Entry<K, Collection<V>>> mapEntries = builderMap.entrySet();
+            if (keyComparator != null) {
+                mapEntries = Ordering.from(keyComparator).<K>onKeys().immutableSortedCopy(mapEntries);
+            }
+            return fromMapEntries(mapEntries, valueComparator);
+        }
+    }
+
+    /**
+     * Returns an immutable set multimap containing the same mappings as {@code multimap}. The
+     * generated multimap's key and value orderings correspond to the iteration ordering of the {@code
+     * multimap.asMap()} view. Repeated occurrences of an entry in the multimap after the first are
+     * ignored.
+     *
+     * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
+     * safe to do so. The exact circumstances under which a copy will or will not be performed are
+     * undocumented and subject to change.
+     *
+     * @throws NullPointerException if any key or value in {@code multimap} is null
+     */
+    public static <K, V> ImmutableSetMultimap<K, V> copyOf(
+            Multimap<? extends K, ? extends V> multimap) {
+        return copyOf(multimap, null);
+    }
+
+    private static <K, V> ImmutableSetMultimap<K, V> copyOf(
+            Multimap<? extends K, ? extends V> multimap,
+            Comparator<? super V> valueComparator) {
+        checkNotNull(multimap); // eager for GWT
+        if (multimap.isEmpty() && valueComparator == null) {
+            return of();
+        }
+
+        if (multimap instanceof ImmutableSetMultimap) {
+            @SuppressWarnings("unchecked") // safe since multimap is not writable
+            ImmutableSetMultimap<K, V> kvMultimap = (ImmutableSetMultimap<K, V>) multimap;
+            if (!kvMultimap.isPartialView()) {
+                return kvMultimap;
+            }
+        }
+
+        return fromMapEntries(multimap.asMap().entrySet(), valueComparator);
+    }
+
+    /**
+     * Returns an immutable multimap containing the specified entries. The returned multimap iterates
+     * over keys in the order they were first encountered in the input, and the values for each key
+     * are iterated in the order they were encountered. If two values for the same key are {@linkplain
+     * Object#equals equal}, the first value encountered is used.
+     *
+     * @throws NullPointerException if any key, value, or entry is null
+     */
+    public static <K, V> ImmutableSetMultimap<K, V> copyOf(
+            Iterable<? extends Entry<? extends K, ? extends V>> entries) {
+        return new Builder<K, V>().putAll(entries).build();
+    }
+
+    /**
+     * Creates an ImmutableSetMultimap from an asMap.entrySet.
+     */
+    static <K, V> ImmutableSetMultimap<K, V> fromMapEntries(
+            Collection<? extends Entry<? extends K, ? extends Collection<? extends V>>> mapEntries,
+            Comparator<? super V> valueComparator) {
+        if (mapEntries.isEmpty()) {
+            return of();
+        }
+        ImmutableMap.Builder<K, ImmutableSet<V>> builder =
+                new ImmutableMap.Builder<>(mapEntries.size());
+        int size = 0;
+
+        for (Entry<? extends K, ? extends Collection<? extends V>> entry : mapEntries) {
+            K key = entry.getKey();
+            Collection<? extends V> values = entry.getValue();
+            ImmutableSet<V> set = valueSet(valueComparator, values);
+            if (!set.isEmpty()) {
+                builder.put(key, set);
+                size += set.size();
+            }
+        }
+
+        return new ImmutableSetMultimap<>(builder.buildOrThrow(), size, valueComparator);
+    }
+
+    /**
+     * Returned by get() when a missing key is provided. Also holds the comparator, if any, used for
+     * values.
+     */
+    private final transient ImmutableSet<V> emptySet;
+
+    ImmutableSetMultimap(
+            ImmutableMap<K, ImmutableSet<V>> map,
+            int size,
+            Comparator<? super V> valueComparator) {
+        super(map, size);
+        this.emptySet = emptySet(valueComparator);
+    }
+
+    // views
+
+    /**
+     * Returns an immutable set of the values for the given key. If no mappings in the multimap have
+     * the provided key, an empty immutable set is returned. The values are in the same order as the
+     * parameters used to build this multimap.
+     */
+    @Override
+    public ImmutableSet<V> get(K key) {
+        // This cast is safe as its type is known in constructor.
+        ImmutableSet<V> set = (ImmutableSet<V>) map.get(key);
+        return MoreObjects.firstNonNull(set, emptySet);
+    }
+
+    private transient ImmutableSetMultimap<V, K> inverse;
+
+    /**
+     * {@inheritDoc}
+     *
+     * <p>Because an inverse of a set multimap cannot contain multiple pairs with the same key and
+     * value, this method returns an {@code ImmutableSetMultimap} rather than the {@code
+     * ImmutableMultimap} specified in the {@code ImmutableMultimap} class.
+     */
+    @Override
+    public ImmutableSetMultimap<V, K> inverse() {
+        ImmutableSetMultimap<V, K> result = inverse;
+        return (result == null) ? (inverse = invert()) : result;
+    }
+
+    private ImmutableSetMultimap<V, K> invert() {
+        Builder<V, K> builder = builder();
+        for (Entry<K, V> entry : entries()) {
+            builder.put(entry.getValue(), entry.getKey());
+        }
+        ImmutableSetMultimap<V, K> invertedMultimap = builder.build();
+        invertedMultimap.inverse = this;
+        return invertedMultimap;
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the multimap unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final ImmutableSet<V> removeAll(Object key) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Guaranteed to throw an exception and leave the multimap unmodified.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public final ImmutableSet<V> replaceValues(K key, Iterable<? extends V> values) {
+        throw new UnsupportedOperationException();
+    }
+
+    private transient ImmutableSet<Entry<K, V>> entries;
+
+    /**
+     * Returns an immutable collection of all key-value pairs in the multimap. Its iterator traverses
+     * the values for the first key, the values for the second key, and so on.
+     */
+    @Override
+    public ImmutableSet<Entry<K, V>> entries() {
+        ImmutableSet<Entry<K, V>> result = entries;
+        return result == null ? (entries = new EntrySet<>(this)) : result;
+    }
+
+    private static final class EntrySet<K, V> extends ImmutableSet<Entry<K, V>> {
+        private final transient ImmutableSetMultimap<K, V> multimap;
+
+        EntrySet(ImmutableSetMultimap<K, V> multimap) {
+            this.multimap = multimap;
+        }
+
+        @Override
+        public boolean contains(Object object) {
+            if (object instanceof Entry<?, ?> entry) {
+                return multimap.containsEntry(entry.getKey(), entry.getValue());
+            }
+            return false;
+        }
+
+        @Override
+        public int size() {
+            return multimap.size();
+        }
+
+        @Override
+        public UnmodifiableIterator<Entry<K, V>> iterator() {
+            return multimap.entryIterator();
+        }
+
+        @Override
+        boolean isPartialView() {
+            return false;
+        }
+    }
+
+    private static <V> ImmutableSet<V> valueSet(Comparator<? super V> valueComparator, Collection<? extends V> values) {
+        return (valueComparator == null)
+                ? ImmutableSet.copyOf(values)
+                : ImmutableSortedSet.copyOf(valueComparator, values);
+    }
+
+    private static <V> ImmutableSet<V> emptySet(Comparator<? super V> valueComparator) {
+        return (valueComparator == null)
+                ? ImmutableSet.of()
+                : ImmutableSortedSet.<V>emptySet(valueComparator);
+    }
+
+    private static <V> ImmutableSet.Builder<V> valuesBuilder(Comparator<? super V> valueComparator) {
+        return (valueComparator == null)
+                ? new ImmutableSet.Builder<V>()
+                : new ImmutableSortedSet.Builder<V>(valueComparator);
+    }
+
+    private void writeObject(ObjectOutputStream stream) throws IOException {
+        stream.defaultWriteObject();
+        stream.writeObject(valueComparator());
+        Serialization.writeMultimap(this, stream);
+    }
+
+    Comparator<? super V> valueComparator() {
+        return emptySet instanceof ImmutableSortedSet
+                ? ((ImmutableSortedSet<V>) emptySet).comparator()
+                : null;
+    }
+
+    private static final class SetFieldSettersHolder {
+        static final Serialization.FieldSetter<ImmutableSetMultimap> EMPTY_SET_FIELD_SETTER =
+                Serialization.getFieldSetter(ImmutableSetMultimap.class, "emptySet");
+    }
+
+    @SuppressWarnings("unchecked")
+    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
+        stream.defaultReadObject();
+        Comparator<Object> valueComparator = (Comparator<Object>) stream.readObject();
+        int keyCount = stream.readInt();
+        if (keyCount < 0) {
+            throw new InvalidObjectException("Invalid key count " + keyCount);
+        }
+        ImmutableMap.Builder<Object, ImmutableSet<Object>> builder = ImmutableMap.builder();
+        int tmpSize = 0;
+
+        for (int i = 0; i < keyCount; i++) {
+            Object key = stream.readObject();
+            int valueCount = stream.readInt();
+            if (valueCount <= 0) {
+                throw new InvalidObjectException("Invalid value count " + valueCount);
+            }
+
+            ImmutableSet.Builder<Object> valuesBuilder = valuesBuilder(valueComparator);
+            for (int j = 0; j < valueCount; j++) {
+                valuesBuilder.add(stream.readObject());
+            }
+            ImmutableSet<Object> valueSet = valuesBuilder.build();
+            if (valueSet.size() != valueCount) {
+                throw new InvalidObjectException("Duplicate key-value pairs exist for key " + key);
+            }
+            builder.put(key, valueSet);
+            tmpSize += valueCount;
+        }
+
+        ImmutableMap<Object, ImmutableSet<Object>> tmpMap;
+        try {
+            tmpMap = builder.buildOrThrow();
+        } catch (IllegalArgumentException e) {
+            throw (InvalidObjectException) new InvalidObjectException(e.getMessage(), e);
+        }
+
+        FieldSettersHolder.MAP_FIELD_SETTER.set(this, tmpMap);
+        FieldSettersHolder.SIZE_FIELD_SETTER.set(this, tmpSize);
+        SetFieldSettersHolder.EMPTY_SET_FIELD_SETTER.set(this, emptySet(valueComparator));
+    }
+
+    private static final long serialVersionUID = 0;
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/ImprovedAbstractSet.java

@@ -0,0 +1,63 @@
+package org.xbib.datastructures.multi;
+
+import java.util.AbstractSet;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Objects;
+import java.util.Set;
+import org.xbib.datastructures.api.Multiset;
+
+/**
+ * {@link AbstractSet} substitute without the potentially-quadratic {@code removeAll}
+ * implementation.
+ */
+abstract class ImprovedAbstractSet<E extends Object> extends AbstractSet<E> {
+    @Override
+    public boolean removeAll(Collection<?> c) {
+        return removeAllImpl(this, c);
+    }
+
+    @Override
+    public boolean retainAll(Collection<?> c) {
+        return super.retainAll(Objects.requireNonNull(c));
+    }
+
+    private static boolean removeAllImpl(Set<?> set, Collection<?> collection) {
+        Objects.requireNonNull(collection); // for GWT
+        if (collection instanceof Multiset) {
+            collection = ((Multiset<?>) collection).elementSet();
+        }
+        /*
+         * AbstractSet.removeAll(List) has quadratic behavior if the list size
+         * is just more than the set's size.  We augment the test by
+         * assuming that sets have fast contains() performance, and other
+         * collections don't.
+         */
+        if (collection instanceof Set && collection.size() > set.size()) {
+            return removeAll(set.iterator(), collection);
+        } else {
+            return removeAllImpl(set, collection.iterator());
+        }
+    }
+
+    /** Remove each element in an iterable from a set. */
+    private static boolean removeAllImpl(Set<?> set, Iterator<?> iterator) {
+        boolean changed = false;
+        while (iterator.hasNext()) {
+            changed |= set.remove(iterator.next());
+        }
+        return changed;
+    }
+
+    private static boolean removeAll(Iterator<?> removeFrom, Collection<?> elementsToRemove) {
+        Objects.requireNonNull(elementsToRemove);
+        boolean result = false;
+        while (removeFrom.hasNext()) {
+            if (elementsToRemove.contains(removeFrom.next())) {
+                removeFrom.remove();
+                result = true;
+            }
+        }
+        return result;
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/JdkBackedImmutableMultiset.java

@@ -0,0 +1,80 @@
+package org.xbib.datastructures.multi;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * An implementation of ImmutableMultiset backed by a JDK Map and a list of entries. Used to protect
+ * against hash flooding attacks.
+ */
+final class JdkBackedImmutableMultiset<E> extends ImmutableMultiset<E> {
+    private final Map<E, Integer> delegateMap;
+    private final ImmutableList<Entry<E>> entries;
+    private final long size;
+
+    static <E> ImmutableMultiset<E> create(Collection<? extends Entry<? extends E>> entries) {
+        @SuppressWarnings("unchecked")
+        Entry<E>[] entriesArray = entries.toArray(new Entry[0]);
+        Map<E, Integer> delegateMap = new HashMap<>(entriesArray.length);
+        long size = 0;
+        for (int i = 0; i < entriesArray.length; i++) {
+            Entry<E> entry = entriesArray[i];
+            int count = entry.getCount();
+            size += count;
+            E element = Objects.requireNonNull(entry.getElement());
+            delegateMap.put(element, count);
+            if (!(entry instanceof MultisetsImmutableEntry)) {
+                entriesArray[i] = new MultisetsImmutableEntry<>(element, count);
+            }
+        }
+        return new JdkBackedImmutableMultiset<>(
+                delegateMap, ImmutableList.asImmutableList(entriesArray), size);
+    }
+
+    private JdkBackedImmutableMultiset(
+            Map<E, Integer> delegateMap, ImmutableList<Entry<E>> entries, long size) {
+        this.delegateMap = delegateMap;
+        this.entries = entries;
+        this.size = size;
+    }
+
+    @Override
+    public int count(Object element) {
+        return delegateMap.getOrDefault(element, 0);
+    }
+
+    private transient ImmutableSet<E> elementSet;
+
+    @Override
+    public ImmutableSet<E> elementSet() {
+        ImmutableSet<E> result = elementSet;
+        return (result == null) ? elementSet = new ElementSet<>(entries, this) : result;
+    }
+
+    @Override
+    Entry<E> getEntry(int index) {
+        return entries.get(index);
+    }
+
+    @Override
+    boolean isPartialView() {
+        return false;
+    }
+
+    @Override
+    public int size() {
+        return saturatedCast(size);
+    }
+
+    private static int saturatedCast(long value) {
+        if (value > Integer.MAX_VALUE) {
+            return Integer.MAX_VALUE;
+        }
+        if (value < Integer.MIN_VALUE) {
+            return Integer.MIN_VALUE;
+        }
+        return (int) value;
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/LinkedHashMultimap.java

@@ -0,0 +1,567 @@
+package org.xbib.datastructures.multi;
+
+import static java.util.Objects.requireNonNull;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+import java.util.Map.Entry;
+import java.util.NoSuchElementException;
+import java.util.Set;
+import java.util.Spliterator;
+import java.util.Spliterators;
+import java.util.function.Consumer;
+import org.xbib.datastructures.api.Multimap;
+import org.xbib.datastructures.immutable.ImmutableEntry;
+
+/**
+ * Implementation of {@code Multimap} that does not allow duplicate key-value entries and that
+ * returns collections whose iterators follow the ordering in which the data was added to the
+ * multimap.
+ *
+ * <p>The collections returned by {@code keySet}, {@code keys}, and {@code asMap} iterate through
+ * the keys in the order they were first added to the multimap. Similarly, {@code get}, {@code
+ * removeAll}, and {@code replaceValues} return collections that iterate through the values in the
+ * order they were added. The collections generated by {@code entries} and {@code values} iterate
+ * across the key-value mappings in the order they were added to the multimap.
+ *
+ * <p>The iteration ordering of the collections generated by {@code keySet}, {@code keys}, and
+ * {@code asMap} has a few subtleties. As long as the set of keys remains unchanged, adding or
+ * removing mappings does not affect the key iteration order. However, if you remove all values
+ * associated with a key and then add the key back to the multimap, that key will come last in the
+ * key iteration order.
+ *
+ * <p>The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an
+ * existing key-value pair has no effect.
+ *
+ * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
+ * views are modifiable.
+ *
+ * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
+ * read operations will work correctly. To allow concurrent update operations, wrap your multimap
+ * with a call to {@link Multimaps#synchronizedSetMultimap}.
+ *
+ * <p><b>Warning:</b> Do not modify either a key <i>or a value</i> of a {@code LinkedHashMultimap}
+ * in a way that affects its {@link Object#equals} behavior. Undefined behavior and bugs will
+ * result.
+ *
+ */
+public final class LinkedHashMultimap<K extends Object, V extends Object>
+        extends AbstractSetMultimap<K, V> {
+
+    /** Creates a new, empty {@code LinkedHashMultimap} with the default initial capacities. */
+    public static <K extends Object, V extends Object>
+    LinkedHashMultimap<K, V> create() {
+        return new LinkedHashMultimap<>(DEFAULT_KEY_CAPACITY, DEFAULT_VALUE_SET_CAPACITY);
+    }
+
+    /**
+     * Constructs an empty {@code LinkedHashMultimap} with enough capacity to hold the specified
+     * numbers of keys and values without rehashing.
+     *
+     * @param expectedKeys the expected number of distinct keys
+     * @param expectedValuesPerKey the expected average number of values per key
+     * @throws IllegalArgumentException if {@code expectedKeys} or {@code expectedValuesPerKey} is
+     *     negative
+     */
+    public static <K extends Object, V extends Object>
+    LinkedHashMultimap<K, V> create(int expectedKeys, int expectedValuesPerKey) {
+        return new LinkedHashMultimap<>(
+                Maps.capacity(expectedKeys), Maps.capacity(expectedValuesPerKey));
+    }
+
+    /**
+     * Constructs a {@code LinkedHashMultimap} with the same mappings as the specified multimap. If a
+     * key-value mapping appears multiple times in the input multimap, it only appears once in the
+     * constructed multimap. The new multimap has the same {@link Multimap#entries()} iteration order
+     * as the input multimap, except for excluding duplicate mappings.
+     *
+     * @param multimap the multimap whose contents are copied to this multimap
+     */
+    public static <K extends Object, V extends Object>
+    LinkedHashMultimap<K, V> create(Multimap<? extends K, ? extends V> multimap) {
+        LinkedHashMultimap<K, V> result = create(multimap.keySet().size(), DEFAULT_VALUE_SET_CAPACITY);
+        result.putAll(multimap);
+        return result;
+    }
+
+    private interface ValueSetLink<K extends Object, V extends Object> {
+        ValueSetLink<K, V> getPredecessorInValueSet();
+
+        ValueSetLink<K, V> getSuccessorInValueSet();
+
+        void setPredecessorInValueSet(ValueSetLink<K, V> entry);
+
+        void setSuccessorInValueSet(ValueSetLink<K, V> entry);
+    }
+
+    private static <K extends Object, V extends Object> void succeedsInValueSet(
+            ValueSetLink<K, V> pred, ValueSetLink<K, V> succ) {
+        pred.setSuccessorInValueSet(succ);
+        succ.setPredecessorInValueSet(pred);
+    }
+
+    private static <K extends Object, V extends Object> void succeedsInMultimap(
+            ValueEntry<K, V> pred, ValueEntry<K, V> succ) {
+        pred.setSuccessorInMultimap(succ);
+        succ.setPredecessorInMultimap(pred);
+    }
+
+    private static <K extends Object, V extends Object> void deleteFromValueSet(
+            ValueSetLink<K, V> entry) {
+        succeedsInValueSet(entry.getPredecessorInValueSet(), entry.getSuccessorInValueSet());
+    }
+
+    private static <K extends Object, V extends Object> void deleteFromMultimap(
+            ValueEntry<K, V> entry) {
+        succeedsInMultimap(entry.getPredecessorInMultimap(), entry.getSuccessorInMultimap());
+    }
+
+    /**
+     * LinkedHashMultimap entries are in no less than three coexisting linked lists: a bucket in the
+     * hash table for a {@code Set<V>} associated with a key, the linked list of insertion-ordered
+     * entries in that {@code Set<V>}, and the linked list of entries in the LinkedHashMultimap as a
+     * whole.
+     */
+    static final class ValueEntry<K extends Object, V extends Object>
+            extends ImmutableEntry<K, V> implements ValueSetLink<K, V> {
+        final int smearedValueHash;
+
+        ValueEntry<K, V> nextInValueBucket;
+        /*
+         * The *InValueSet and *InMultimap fields below are null after construction, but we almost
+         * always call succeedsIn*() to initialize them immediately thereafter.
+         *
+         * The exception is the *InValueSet fields of multimapHeaderEntry, which are never set. (That
+         * works out fine as long as we continue to be careful not to try to delete them or iterate
+         * past them.)
+         *
+         * We could consider "lying" and omitting @CheckNotNull from all these fields. Normally, I'm not
+         * a fan of that: What if we someday implement (presumably to be enabled during tests only)
+         * bytecode rewriting that checks for any null value that passes through an API with a
+         * known-non-null type? But that particular problem might not arise here, since we're not
+         * actually reading from the fields in any case in which they might be null (as proven by the
+         * requireNonNull checks below). Plus, we're *already* lying here, since newHeader passes a null
+         * key and value, which we pass to the superconstructor, even though the key and value type for
+         * a given entry might not include null. The right fix for the header problems is probably to
+         * define a separate MultimapLink interface with a separate "header" implementation, which
+         * hopefully could avoid implementing Entry or ValueSetLink at all. (But note that that approach
+         * requires us to define extra classes -- unfortunate under Android.) *Then* we could consider
+         * lying about the fields below on the grounds that we always initialize them just after the
+         * constructor -- an example of the kind of lying that our hypothetical bytecode rewriter would
+         * already have to deal with, thanks to DI frameworks that perform field and method injection,
+         * frameworks like Android that define post-construct hooks like Activity.onCreate, etc.
+         */
+
+        ValueSetLink<K, V> predecessorInValueSet;
+        ValueSetLink<K, V> successorInValueSet;
+
+        ValueEntry<K, V> predecessorInMultimap;
+        ValueEntry<K, V> successorInMultimap;
+
+        ValueEntry(K key, V value,
+                int smearedValueHash,
+                ValueEntry<K, V> nextInValueBucket) {
+            super(key, value);
+            this.smearedValueHash = smearedValueHash;
+            this.nextInValueBucket = nextInValueBucket;
+        }
+
+        @SuppressWarnings("nullness") // see the comment on the class fields, especially about newHeader
+        static <K extends Object, V extends Object> ValueEntry<K, V> newHeader() {
+            return new ValueEntry<>(null, null, 0, null);
+        }
+
+        boolean matchesValue(Object v, int smearedVHash) {
+            return smearedValueHash == smearedVHash && Objects.equal(getValue(), v);
+        }
+
+        @Override
+        public ValueSetLink<K, V> getPredecessorInValueSet() {
+            return requireNonNull(predecessorInValueSet); // see the comment on the class fields
+        }
+
+        @Override
+        public ValueSetLink<K, V> getSuccessorInValueSet() {
+            return requireNonNull(successorInValueSet); // see the comment on the class fields
+        }
+
+        @Override
+        public void setPredecessorInValueSet(ValueSetLink<K, V> entry) {
+            predecessorInValueSet = entry;
+        }
+
+        @Override
+        public void setSuccessorInValueSet(ValueSetLink<K, V> entry) {
+            successorInValueSet = entry;
+        }
+
+        public ValueEntry<K, V> getPredecessorInMultimap() {
+            return requireNonNull(predecessorInMultimap); // see the comment on the class fields
+        }
+
+        public ValueEntry<K, V> getSuccessorInMultimap() {
+            return requireNonNull(successorInMultimap); // see the comment on the class fields
+        }
+
+        public void setSuccessorInMultimap(ValueEntry<K, V> multimapSuccessor) {
+            this.successorInMultimap = multimapSuccessor;
+        }
+
+        public void setPredecessorInMultimap(ValueEntry<K, V> multimapPredecessor) {
+            this.predecessorInMultimap = multimapPredecessor;
+        }
+    }
+
+    private static final int DEFAULT_KEY_CAPACITY = 16;
+    private static final int DEFAULT_VALUE_SET_CAPACITY = 2;
+    static final double VALUE_SET_LOAD_FACTOR = 1.0;
+
+    transient int valueSetCapacity = DEFAULT_VALUE_SET_CAPACITY;
+    private transient ValueEntry<K, V> multimapHeaderEntry;
+
+    private LinkedHashMultimap(int keyCapacity, int valueSetCapacity) {
+        super(Platform.<K, Collection<V>>newLinkedHashMapWithExpectedSize(keyCapacity));
+        checkNonnegative(valueSetCapacity, "expectedValuesPerKey");
+
+        this.valueSetCapacity = valueSetCapacity;
+        this.multimapHeaderEntry = ValueEntry.newHeader();
+        succeedsInMultimap(multimapHeaderEntry, multimapHeaderEntry);
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * <p>Creates an empty {@code LinkedHashSet} for a collection of values for one key.
+     *
+     * @return a new {@code LinkedHashSet} containing a collection of values for one key
+     */
+    @Override
+    Set<V> createCollection() {
+        return Platform.newLinkedHashSetWithExpectedSize(valueSetCapacity);
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * <p>Creates a decorated insertion-ordered set that also keeps track of the order in which
+     * key-value pairs are added to the multimap.
+     *
+     * @param key key to associate with values in the collection
+     * @return a new decorated set containing a collection of values for one key
+     */
+    @Override
+    Collection<V> createCollection(K key) {
+        return new ValueSet(key, valueSetCapacity);
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * <p>If {@code values} is not empty and the multimap already contains a mapping for {@code key},
+     * the {@code keySet()} ordering is unchanged. However, the provided values always come last in
+     * the {@link #entries()} and {@link #values()} iteration orderings.
+     */
+    @Override
+    public Set<V> replaceValues(K key, Iterable<? extends V> values) {
+        return super.replaceValues(key, values);
+    }
+
+    /**
+     * Returns a set of all key-value pairs. Changes to the returned set will update the underlying
+     * multimap, and vice versa. The entries set does not support the {@code add} or {@code addAll}
+     * operations.
+     *
+     * <p>The iterator generated by the returned set traverses the entries in the order they were
+     * added to the multimap.
+     *
+     * <p>Each entry is an immutable snapshot of a key-value mapping in the multimap, taken at the
+     * time the entry is returned by a method call to the collection or its iterator.
+     */
+    @Override
+    public Set<Entry<K, V>> entries() {
+        return super.entries();
+    }
+
+    /**
+     * Returns a view collection of all <i>distinct</i> keys contained in this multimap. Note that the
+     * key set contains a key if and only if this multimap maps that key to at least one value.
+     *
+     * <p>The iterator generated by the returned set traverses the keys in the order they were first
+     * added to the multimap.
+     *
+     * <p>Changes to the returned set will update the underlying multimap, and vice versa. However,
+     * <i>adding</i> to the returned set is not possible.
+     */
+    @Override
+    public Set<K> keySet() {
+        return super.keySet();
+    }
+
+    /**
+     * Returns a collection of all values in the multimap. Changes to the returned collection will
+     * update the underlying multimap, and vice versa.
+     *
+     * <p>The iterator generated by the returned collection traverses the values in the order they
+     * were added to the multimap.
+     */
+    @Override
+    public Collection<V> values() {
+        return super.values();
+    }
+
+    final class ValueSet extends ImprovedAbstractSet<V> implements ValueSetLink<K, V> {
+        /*
+         * We currently use a fixed load factor of 1.0, a bit higher than normal to reduce memory
+         * consumption.
+         */
+
+        private final K key;
+        ValueEntry<K, V>[] hashTable;
+        private int size = 0;
+        private int modCount = 0;
+
+        // We use the set object itself as the end of the linked list, avoiding an unnecessary
+        // entry object per key.
+        private ValueSetLink<K, V> firstEntry;
+        private ValueSetLink<K, V> lastEntry;
+
+        ValueSet(K key, int expectedValues) {
+            this.key = key;
+            this.firstEntry = this;
+            this.lastEntry = this;
+            // Round expected values up to a power of 2 to get the table size.
+            int tableSize = Hashing.closedTableSize(expectedValues, VALUE_SET_LOAD_FACTOR);
+
+            @SuppressWarnings({"rawtypes", "unchecked"})
+            ValueEntry<K, V>[] hashTable = new ValueEntry[tableSize];
+            this.hashTable = hashTable;
+        }
+
+        private int mask() {
+            return hashTable.length - 1;
+        }
+
+        @Override
+        public ValueSetLink<K, V> getPredecessorInValueSet() {
+            return lastEntry;
+        }
+
+        @Override
+        public ValueSetLink<K, V> getSuccessorInValueSet() {
+            return firstEntry;
+        }
+
+        @Override
+        public void setPredecessorInValueSet(ValueSetLink<K, V> entry) {
+            lastEntry = entry;
+        }
+
+        @Override
+        public void setSuccessorInValueSet(ValueSetLink<K, V> entry) {
+            firstEntry = entry;
+        }
+
+        @Override
+        public Iterator<V> iterator() {
+            return new Iterator<V>() {
+                ValueSetLink<K, V> nextEntry = firstEntry;
+                ValueEntry<K, V> toRemove;
+                int expectedModCount = modCount;
+
+                private void checkForComodification() {
+                    if (modCount != expectedModCount) {
+                        throw new ConcurrentModificationException();
+                    }
+                }
+
+                @Override
+                public boolean hasNext() {
+                    checkForComodification();
+                    return nextEntry != ValueSet.this;
+                }
+
+                @Override
+                public V next() {
+                    if (!hasNext()) {
+                        throw new NoSuchElementException();
+                    }
+                    ValueEntry<K, V> entry = (ValueEntry<K, V>) nextEntry;
+                    V result = entry.getValue();
+                    toRemove = entry;
+                    nextEntry = entry.getSuccessorInValueSet();
+                    return result;
+                }
+
+                @Override
+                public void remove() {
+                    checkForComodification();
+                    checkState(toRemove != null, "no calls to next() since the last call to remove()");
+                    ValueSet.this.remove(toRemove.getValue());
+                    expectedModCount = modCount;
+                    toRemove = null;
+                }
+            };
+        }
+
+        @Override
+        public void forEach(Consumer<? super V> action) {
+            checkNotNull(action);
+            for (ValueSetLink<K, V> entry = firstEntry;
+                 entry != ValueSet.this;
+                 entry = entry.getSuccessorInValueSet()) {
+                action.accept(((ValueEntry<K, V>) entry).getValue());
+            }
+        }
+
+        @Override
+        public int size() {
+            return size;
+        }
+
+        @Override
+        public boolean contains(Object o) {
+            int smearedHash = Hashing.smearedHash(o);
+            for (ValueEntry<K, V> entry = hashTable[smearedHash & mask()];
+                 entry != null;
+                 entry = entry.nextInValueBucket) {
+                if (entry.matchesValue(o, smearedHash)) {
+                    return true;
+                }
+            }
+            return false;
+        }
+
+        @Override
+        public boolean add(V value) {
+            int smearedHash = Hashing.smearedHash(value);
+            int bucket = smearedHash & mask();
+            ValueEntry<K, V> rowHead = hashTable[bucket];
+            for (ValueEntry<K, V> entry = rowHead; entry != null; entry = entry.nextInValueBucket) {
+                if (entry.matchesValue(value, smearedHash)) {
+                    return false;
+                }
+            }
+
+            ValueEntry<K, V> newEntry = new ValueEntry<>(key, value, smearedHash, rowHead);
+            succeedsInValueSet(lastEntry, newEntry);
+            succeedsInValueSet(newEntry, this);
+            succeedsInMultimap(multimapHeaderEntry.getPredecessorInMultimap(), newEntry);
+            succeedsInMultimap(newEntry, multimapHeaderEntry);
+            hashTable[bucket] = newEntry;
+            size++;
+            modCount++;
+            rehashIfNecessary();
+            return true;
+        }
+
+        private void rehashIfNecessary() {
+            if (Hashing.needsResizing(size, hashTable.length, VALUE_SET_LOAD_FACTOR)) {
+                @SuppressWarnings("unchecked")
+                ValueEntry<K, V>[] hashTable = new ValueEntry[this.hashTable.length * 2];
+                this.hashTable = hashTable;
+                int mask = hashTable.length - 1;
+                for (ValueSetLink<K, V> entry = firstEntry;
+                     entry != this;
+                     entry = entry.getSuccessorInValueSet()) {
+                    ValueEntry<K, V> valueEntry = (ValueEntry<K, V>) entry;
+                    int bucket = valueEntry.smearedValueHash & mask;
+                    valueEntry.nextInValueBucket = hashTable[bucket];
+                    hashTable[bucket] = valueEntry;
+                }
+            }
+        }
+
+        @Override
+        public boolean remove(Object o) {
+            int smearedHash = Hashing.smearedHash(o);
+            int bucket = smearedHash & mask();
+            ValueEntry<K, V> prev = null;
+            for (ValueEntry<K, V> entry = hashTable[bucket];
+                 entry != null;
+                 prev = entry, entry = entry.nextInValueBucket) {
+                if (entry.matchesValue(o, smearedHash)) {
+                    if (prev == null) {
+                        // first entry in the bucket
+                        hashTable[bucket] = entry.nextInValueBucket;
+                    } else {
+                        prev.nextInValueBucket = entry.nextInValueBucket;
+                    }
+                    deleteFromValueSet(entry);
+                    deleteFromMultimap(entry);
+                    size--;
+                    modCount++;
+                    return true;
+                }
+            }
+            return false;
+        }
+
+        @Override
+        public void clear() {
+            Arrays.fill(hashTable, null);
+            size = 0;
+            for (ValueSetLink<K, V> entry = firstEntry;
+                 entry != this;
+                 entry = entry.getSuccessorInValueSet()) {
+                ValueEntry<K, V> valueEntry = (ValueEntry<K, V>) entry;
+                deleteFromMultimap(valueEntry);
+            }
+            succeedsInValueSet(this, this);
+            modCount++;
+        }
+    }
+
+    @Override
+    Iterator<Entry<K, V>> entryIterator() {
+        return new Iterator<Entry<K, V>>() {
+            ValueEntry<K, V> nextEntry = multimapHeaderEntry.getSuccessorInMultimap();
+            ValueEntry<K, V> toRemove;
+
+            @Override
+            public boolean hasNext() {
+                return nextEntry != multimapHeaderEntry;
+            }
+
+            @Override
+            public Entry<K, V> next() {
+                if (!hasNext()) {
+                    throw new NoSuchElementException();
+                }
+                ValueEntry<K, V> result = nextEntry;
+                toRemove = result;
+                nextEntry = nextEntry.getSuccessorInMultimap();
+                return result;
+            }
+
+            @Override
+            public void remove() {
+                checkState(toRemove != null, "no calls to next() since the last call to remove()");
+                LinkedHashMultimap.this.remove(toRemove.getKey(), toRemove.getValue());
+                toRemove = null;
+            }
+        };
+    }
+
+    @Override
+    Spliterator<Entry<K, V>> entrySpliterator() {
+        return Spliterators.spliterator(entries(), Spliterator.DISTINCT | Spliterator.ORDERED);
+    }
+
+    @Override
+    Iterator<V> valueIterator() {
+        return Maps.valueIterator(entryIterator());
+    }
+
+    @Override
+    Spliterator<V> valueSpliterator() {
+        return CollectSpliterators.map(entrySpliterator(), Entry::getValue);
+    }
+
+    @Override
+    public void clear() {
+        super.clear();
+        succeedsInMultimap(multimapHeaderEntry, multimapHeaderEntry);
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/LinkedHashMultiset.java

@@ -0,0 +1,53 @@
+package org.xbib.datastructures.multi;
+
+import org.xbib.datastructures.api.Multiset;
+
+/**
+ * A {@code Multiset} implementation with predictable iteration order. Its iterator orders elements
+ * according to when the first occurrence of the element was added. When the multiset contains
+ * multiple instances of an element, those instances are consecutive in the iteration order. If all
+ * occurrences of an element are removed, after which that element is added to the multiset, the
+ * element will appear at the end of the iteration.
+ *
+ */
+public final class LinkedHashMultiset<E extends Object>
+        extends AbstractMapBasedMultiset<E> {
+
+    /** Creates a new, empty {@code LinkedHashMultiset} using the default initial capacity. */
+    public static <E extends Object> LinkedHashMultiset<E> create() {
+        return new LinkedHashMultiset<E>();
+    }
+
+    /**
+     * Creates a new, empty {@code LinkedHashMultiset} with the specified expected number of distinct
+     * elements.
+     *
+     * @param distinctElements the expected number of distinct elements
+     * @throws IllegalArgumentException if {@code distinctElements} is negative
+     */
+    public static <E extends Object> LinkedHashMultiset<E> create(int distinctElements) {
+        return new LinkedHashMultiset<E>(distinctElements);
+    }
+
+    /**
+     * Creates a new {@code LinkedHashMultiset} containing the specified elements.
+     *
+     * <p>This implementation is highly efficient when {@code elements} is itself a {@link Multiset}.
+     *
+     * @param elements the elements that the multiset should contain
+     */
+    public static <E extends Object> LinkedHashMultiset<E> create(
+            Iterable<? extends E> elements) {
+        LinkedHashMultiset<E> multiset = create(Multisets.inferDistinctElements(elements));
+        Iterables.addAll(multiset, elements);
+        return multiset;
+    }
+
+    private LinkedHashMultiset() {
+        super(new LinkedHashMap<E, Count>());
+    }
+
+    private LinkedHashMultiset(int distinctElements) {
+        super(Maps.<E, Count>newLinkedHashMapWithExpectedSize(distinctElements));
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/LinkedListMultimap.java

@@ -0,0 +1,866 @@
+package org.xbib.datastructures.multi;
+
+import static java.util.Collections.unmodifiableList;
+import static java.util.Objects.requireNonNull;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+import java.util.AbstractSequentialList;
+import java.util.Collection;
+import java.util.ConcurrentModificationException;
+import java.util.Iterator;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.NoSuchElementException;
+import java.util.Set;
+import java.util.function.Consumer;
+
+/**
+ * An implementation of {@code ListMultimap} that supports deterministic iteration order for both
+ * keys and values. The iteration order is preserved across non-distinct key values. For example,
+ * for the following multimap definition:
+ *
+ * <pre>{@code
+ * Multimap<K, V> multimap = LinkedListMultimap.create();
+ * multimap.put(key1, foo);
+ * multimap.put(key2, bar);
+ * multimap.put(key1, baz);
+ * }</pre>
+ *
+ * ... the iteration order for {@link #keys()} is {@code [key1, key2, key1]}, and similarly for
+ * {@link #entries()}. Unlike {@link LinkedHashMultimap}, the iteration order is kept consistent
+ * between keys, entries and values. For example, calling:
+ *
+ * <pre>{@code
+ * multimap.remove(key1, foo);
+ * }</pre>
+ *
+ * <p>changes the entries iteration order to {@code [key2=bar, key1=baz]} and the key iteration
+ * order to {@code [key2, key1]}. The {@link #entries()} iterator returns mutable map entries, and
+ * {@link #replaceValues} attempts to preserve iteration order as much as possible.
+ *
+ * <p>The collections returned by {@link #keySet()} and {@link #asMap} iterate through the keys in
+ * the order they were first added to the multimap. Similarly, {@link #get}, {@link #removeAll}, and
+ * {@link #replaceValues} return collections that iterate through the values in the order they were
+ * added. The collections generated by {@link #entries()}, {@link #keys()}, and {@link #values}
+ * iterate across the key-value mappings in the order they were added to the multimap.
+ *
+ * <p>The {@link #values()} and {@link #entries()} methods both return a {@code List}, instead of
+ * the {@code Collection} specified by the {@link ListMultimap} interface.
+ *
+ * <p>The methods {@link #get}, {@link #keySet()}, {@link #keys()}, {@link #values}, {@link
+ * #entries()}, and {@link #asMap} return collections that are views of the multimap. If the
+ * multimap is modified while an iteration over any of those collections is in progress, except
+ * through the iterator's methods, the results of the iteration are undefined.
+ *
+ * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
+ * views are modifiable.
+ *
+ * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
+ * read operations will work correctly. To allow concurrent update operations, wrap your multimap
+ * with a call to {@link Multimaps#synchronizedListMultimap}.
+ *
+ * <p>See the Guava User Guide article on <a href=
+ * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multimap">{@code Multimap}</a>.
+ *
+ * @author Mike Bostock
+ * @since 2.0
+ */
+@GwtCompatible(serializable = true, emulated = true)
+@ElementTypesAreNonnullByDefault
+public class LinkedListMultimap<K extends @Nullable Object, V extends @Nullable Object>
+    extends AbstractMultimap<K, V> implements ListMultimap<K, V>, Serializable {
+  /*
+   * Order is maintained using a linked list containing all key-value pairs. In
+   * addition, a series of disjoint linked lists of "siblings", each containing
+   * the values for a specific key, is used to implement {@link
+   * ValueForKeyIterator} in constant time.
+   */
+
+  private static final class Node<K extends @Nullable Object, V extends @Nullable Object>
+      extends AbstractMapEntry<K, V> {
+    @ParametricNullness final K key;
+    @ParametricNullness V value;
+    @CheckForNull Node<K, V> next; // the next node (with any key)
+    @CheckForNull Node<K, V> previous; // the previous node (with any key)
+    @CheckForNull Node<K, V> nextSibling; // the next node with the same key
+    @CheckForNull Node<K, V> previousSibling; // the previous node with the same key
+
+    Node(@ParametricNullness K key, @ParametricNullness V value) {
+      this.key = key;
+      this.value = value;
+    }
+
+    @Override
+    @ParametricNullness
+    public K getKey() {
+      return key;
+    }
+
+    @Override
+    @ParametricNullness
+    public V getValue() {
+      return value;
+    }
+
+    @Override
+    @ParametricNullness
+    public V setValue(@ParametricNullness V newValue) {
+      V result = value;
+      this.value = newValue;
+      return result;
+    }
+  }
+
+  private static class KeyList<K extends @Nullable Object, V extends @Nullable Object> {
+    Node<K, V> head;
+    Node<K, V> tail;
+    int count;
+
+    KeyList(Node<K, V> firstNode) {
+      this.head = firstNode;
+      this.tail = firstNode;
+      firstNode.previousSibling = null;
+      firstNode.nextSibling = null;
+      this.count = 1;
+    }
+  }
+
+  @CheckForNull private transient Node<K, V> head; // the head for all keys
+  @CheckForNull private transient Node<K, V> tail; // the tail for all keys
+  private transient Map<K, KeyList<K, V>> keyToKeyList;
+  private transient int size;
+
+  /*
+   * Tracks modifications to keyToKeyList so that addition or removal of keys invalidates
+   * preexisting iterators. This does *not* track simple additions and removals of values
+   * that are not the first to be added or last to be removed for their key.
+   */
+  private transient int modCount;
+
+  /** Creates a new, empty {@code LinkedListMultimap} with the default initial capacity. */
+  public static <K extends @Nullable Object, V extends @Nullable Object>
+      LinkedListMultimap<K, V> create() {
+    return new LinkedListMultimap<>();
+  }
+
+  /**
+   * Constructs an empty {@code LinkedListMultimap} with enough capacity to hold the specified
+   * number of keys without rehashing.
+   *
+   * @param expectedKeys the expected number of distinct keys
+   * @throws IllegalArgumentException if {@code expectedKeys} is negative
+   */
+  public static <K extends @Nullable Object, V extends @Nullable Object>
+      LinkedListMultimap<K, V> create(int expectedKeys) {
+    return new LinkedListMultimap<>(expectedKeys);
+  }
+
+  /**
+   * Constructs a {@code LinkedListMultimap} with the same mappings as the specified {@code
+   * Multimap}. The new multimap has the same {@link Multimap#entries()} iteration order as the
+   * input multimap.
+   *
+   * @param multimap the multimap whose contents are copied to this multimap
+   */
+  public static <K extends @Nullable Object, V extends @Nullable Object>
+      LinkedListMultimap<K, V> create(Multimap<? extends K, ? extends V> multimap) {
+    return new LinkedListMultimap<>(multimap);
+  }
+
+  LinkedListMultimap() {
+    this(12);
+  }
+
+  private LinkedListMultimap(int expectedKeys) {
+    keyToKeyList = Platform.newHashMapWithExpectedSize(expectedKeys);
+  }
+
+  private LinkedListMultimap(Multimap<? extends K, ? extends V> multimap) {
+    this(multimap.keySet().size());
+    putAll(multimap);
+  }
+
+  /**
+   * Adds a new node for the specified key-value pair before the specified {@code nextSibling}
+   * element, or at the end of the list if {@code nextSibling} is null. Note: if {@code nextSibling}
+   * is specified, it MUST be for a node for the same {@code key}!
+   */
+  @CanIgnoreReturnValue
+  private Node<K, V> addNode(
+      @ParametricNullness K key,
+      @ParametricNullness V value,
+      @CheckForNull Node<K, V> nextSibling) {
+    Node<K, V> node = new Node<>(key, value);
+    if (head == null) { // empty list
+      head = tail = node;
+      keyToKeyList.put(key, new KeyList<K, V>(node));
+      modCount++;
+    } else if (nextSibling == null) { // non-empty list, add to tail
+      // requireNonNull is safe because the list is non-empty.
+      requireNonNull(tail).next = node;
+      node.previous = tail;
+      tail = node;
+      KeyList<K, V> keyList = keyToKeyList.get(key);
+      if (keyList == null) {
+        keyToKeyList.put(key, keyList = new KeyList<>(node));
+        modCount++;
+      } else {
+        keyList.count++;
+        Node<K, V> keyTail = keyList.tail;
+        keyTail.nextSibling = node;
+        node.previousSibling = keyTail;
+        keyList.tail = node;
+      }
+    } else { // non-empty list, insert before nextSibling
+      /*
+       * requireNonNull is safe as long as callers pass a nextSibling that (a) has the same key and
+       * (b) is present in the multimap. (And they do, except maybe in case of concurrent
+       * modification, in which case all bets are off.)
+       */
+      KeyList<K, V> keyList = requireNonNull(keyToKeyList.get(key));
+      keyList.count++;
+      node.previous = nextSibling.previous;
+      node.previousSibling = nextSibling.previousSibling;
+      node.next = nextSibling;
+      node.nextSibling = nextSibling;
+      if (nextSibling.previousSibling == null) { // nextSibling was key head
+        keyList.head = node;
+      } else {
+        nextSibling.previousSibling.nextSibling = node;
+      }
+      if (nextSibling.previous == null) { // nextSibling was head
+        head = node;
+      } else {
+        nextSibling.previous.next = node;
+      }
+      nextSibling.previous = node;
+      nextSibling.previousSibling = node;
+    }
+    size++;
+    return node;
+  }
+
+  /**
+   * Removes the specified node from the linked list. This method is only intended to be used from
+   * the {@code Iterator} classes. See also {@link LinkedListMultimap#removeAllNodes(Object)}.
+   */
+  private void removeNode(Node<K, V> node) {
+    if (node.previous != null) {
+      node.previous.next = node.next;
+    } else { // node was head
+      head = node.next;
+    }
+    if (node.next != null) {
+      node.next.previous = node.previous;
+    } else { // node was tail
+      tail = node.previous;
+    }
+    if (node.previousSibling == null && node.nextSibling == null) {
+      /*
+       * requireNonNull is safe as long as we call removeNode only for nodes that are still in the
+       * Multimap. This should be the case (except in case of concurrent modification, when all bets
+       * are off).
+       */
+      KeyList<K, V> keyList = requireNonNull(keyToKeyList.remove(node.key));
+      keyList.count = 0;
+      modCount++;
+    } else {
+      // requireNonNull is safe (under the conditions listed in the comment in the branch above).
+      KeyList<K, V> keyList = requireNonNull(keyToKeyList.get(node.key));
+      keyList.count--;
+
+      if (node.previousSibling == null) {
+        // requireNonNull is safe because we checked that not *both* siblings were null.
+        keyList.head = requireNonNull(node.nextSibling);
+      } else {
+        node.previousSibling.nextSibling = node.nextSibling;
+      }
+
+      if (node.nextSibling == null) {
+        // requireNonNull is safe because we checked that not *both* siblings were null.
+        keyList.tail = requireNonNull(node.previousSibling);
+      } else {
+        node.nextSibling.previousSibling = node.previousSibling;
+      }
+    }
+    size--;
+  }
+
+  /** Removes all nodes for the specified key. */
+  private void removeAllNodes(@ParametricNullness K key) {
+    Iterators.clear(new ValueForKeyIterator(key));
+  }
+
+  /** An {@code Iterator} over all nodes. */
+  private class NodeIterator implements ListIterator<Entry<K, V>> {
+    int nextIndex;
+    @CheckForNull Node<K, V> next;
+    @CheckForNull Node<K, V> current;
+    @CheckForNull Node<K, V> previous;
+    int expectedModCount = modCount;
+
+    NodeIterator(int index) {
+      int size = size();
+      checkPositionIndex(index, size);
+      if (index >= (size / 2)) {
+        previous = tail;
+        nextIndex = size;
+        while (index++ < size) {
+          previous();
+        }
+      } else {
+        next = head;
+        while (index-- > 0) {
+          next();
+        }
+      }
+      current = null;
+    }
+
+    private void checkForConcurrentModification() {
+      if (modCount != expectedModCount) {
+        throw new ConcurrentModificationException();
+      }
+    }
+
+    @Override
+    public boolean hasNext() {
+      checkForConcurrentModification();
+      return next != null;
+    }
+
+    @CanIgnoreReturnValue
+    @Override
+    public Node<K, V> next() {
+      checkForConcurrentModification();
+      if (next == null) {
+        throw new NoSuchElementException();
+      }
+      previous = current = next;
+      next = next.next;
+      nextIndex++;
+      return current;
+    }
+
+    @Override
+    public void remove() {
+      checkForConcurrentModification();
+      checkState(current != null, "no calls to next() since the last call to remove()");
+      if (current != next) { // after call to next()
+        previous = current.previous;
+        nextIndex--;
+      } else { // after call to previous()
+        next = current.next;
+      }
+      removeNode(current);
+      current = null;
+      expectedModCount = modCount;
+    }
+
+    @Override
+    public boolean hasPrevious() {
+      checkForConcurrentModification();
+      return previous != null;
+    }
+
+    @CanIgnoreReturnValue
+    @Override
+    public Node<K, V> previous() {
+      checkForConcurrentModification();
+      if (previous == null) {
+        throw new NoSuchElementException();
+      }
+      next = current = previous;
+      previous = previous.previous;
+      nextIndex--;
+      return current;
+    }
+
+    @Override
+    public int nextIndex() {
+      return nextIndex;
+    }
+
+    @Override
+    public int previousIndex() {
+      return nextIndex - 1;
+    }
+
+    @Override
+    public void set(Entry<K, V> e) {
+      throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public void add(Entry<K, V> e) {
+      throw new UnsupportedOperationException();
+    }
+
+    void setValue(@ParametricNullness V value) {
+      checkState(current != null);
+      current.value = value;
+    }
+  }
+
+  /** An {@code Iterator} over distinct keys in key head order. */
+  private class DistinctKeyIterator implements Iterator<K> {
+    final Set<K> seenKeys = Sets.<K>newHashSetWithExpectedSize(keySet().size());
+    @CheckForNull Node<K, V> next = head;
+    @CheckForNull Node<K, V> current;
+    int expectedModCount = modCount;
+
+    private void checkForConcurrentModification() {
+      if (modCount != expectedModCount) {
+        throw new ConcurrentModificationException();
+      }
+    }
+
+    @Override
+    public boolean hasNext() {
+      checkForConcurrentModification();
+      return next != null;
+    }
+
+    @Override
+    @ParametricNullness
+    public K next() {
+      checkForConcurrentModification();
+      if (next == null) {
+        throw new NoSuchElementException();
+      }
+      current = next;
+      seenKeys.add(current.key);
+      do { // skip ahead to next unseen key
+        next = next.next;
+      } while ((next != null) && !seenKeys.add(next.key));
+      return current.key;
+    }
+
+    @Override
+    public void remove() {
+      checkForConcurrentModification();
+      checkState(current != null, "no calls to next() since the last call to remove()");
+      removeAllNodes(current.key);
+      current = null;
+      expectedModCount = modCount;
+    }
+  }
+
+  /** A {@code ListIterator} over values for a specified key. */
+  private class ValueForKeyIterator implements ListIterator<V> {
+    @ParametricNullness final K key;
+    int nextIndex;
+    @CheckForNull Node<K, V> next;
+    @CheckForNull Node<K, V> current;
+    @CheckForNull Node<K, V> previous;
+
+    /** Constructs a new iterator over all values for the specified key. */
+    ValueForKeyIterator(@ParametricNullness K key) {
+      this.key = key;
+      KeyList<K, V> keyList = keyToKeyList.get(key);
+      next = (keyList == null) ? null : keyList.head;
+    }
+
+    /**
+     * Constructs a new iterator over all values for the specified key starting at the specified
+     * index. This constructor is optimized so that it starts at either the head or the tail,
+     * depending on which is closer to the specified index. This allows adds to the tail to be done
+     * in constant time.
+     *
+     * @throws IndexOutOfBoundsException if index is invalid
+     */
+    public ValueForKeyIterator(@ParametricNullness K key, int index) {
+      KeyList<K, V> keyList = keyToKeyList.get(key);
+      int size = (keyList == null) ? 0 : keyList.count;
+      checkPositionIndex(index, size);
+      if (index >= (size / 2)) {
+        previous = (keyList == null) ? null : keyList.tail;
+        nextIndex = size;
+        while (index++ < size) {
+          previous();
+        }
+      } else {
+        next = (keyList == null) ? null : keyList.head;
+        while (index-- > 0) {
+          next();
+        }
+      }
+      this.key = key;
+      current = null;
+    }
+
+    @Override
+    public boolean hasNext() {
+      return next != null;
+    }
+
+    @CanIgnoreReturnValue
+    @Override
+    @ParametricNullness
+    public V next() {
+      if (next == null) {
+        throw new NoSuchElementException();
+      }
+      previous = current = next;
+      next = next.nextSibling;
+      nextIndex++;
+      return current.value;
+    }
+
+    @Override
+    public boolean hasPrevious() {
+      return previous != null;
+    }
+
+    @CanIgnoreReturnValue
+    @Override
+    @ParametricNullness
+    public V previous() {
+      if (previous == null) {
+        throw new NoSuchElementException();
+      }
+      next = current = previous;
+      previous = previous.previousSibling;
+      nextIndex--;
+      return current.value;
+    }
+
+    @Override
+    public int nextIndex() {
+      return nextIndex;
+    }
+
+    @Override
+    public int previousIndex() {
+      return nextIndex - 1;
+    }
+
+    @Override
+    public void remove() {
+      checkState(current != null, "no calls to next() since the last call to remove()");
+      if (current != next) { // after call to next()
+        previous = current.previousSibling;
+        nextIndex--;
+      } else { // after call to previous()
+        next = current.nextSibling;
+      }
+      removeNode(current);
+      current = null;
+    }
+
+    @Override
+    public void set(@ParametricNullness V value) {
+      checkState(current != null);
+      current.value = value;
+    }
+
+    @Override
+    public void add(@ParametricNullness V value) {
+      previous = addNode(key, value, next);
+      nextIndex++;
+      current = null;
+    }
+  }
+
+  // Query Operations
+
+  @Override
+  public int size() {
+    return size;
+  }
+
+  @Override
+  public boolean isEmpty() {
+    return head == null;
+  }
+
+  @Override
+  public boolean containsKey(@CheckForNull Object key) {
+    return keyToKeyList.containsKey(key);
+  }
+
+  @Override
+  public boolean containsValue(@CheckForNull Object value) {
+    return values().contains(value);
+  }
+
+  // Modification Operations
+
+  /**
+   * Stores a key-value pair in the multimap.
+   *
+   * @param key key to store in the multimap
+   * @param value value to store in the multimap
+   * @return {@code true} always
+   */
+  @CanIgnoreReturnValue
+  @Override
+  public boolean put(@ParametricNullness K key, @ParametricNullness V value) {
+    addNode(key, value, null);
+    return true;
+  }
+
+  // Bulk Operations
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>If any entries for the specified {@code key} already exist in the multimap, their values are
+   * changed in-place without affecting the iteration order.
+   *
+   * <p>The returned list is immutable and implements {@link java.util.RandomAccess}.
+   */
+  @CanIgnoreReturnValue
+  @Override
+  public List<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {
+    List<V> oldValues = getCopy(key);
+    ListIterator<V> keyValues = new ValueForKeyIterator(key);
+    Iterator<? extends V> newValues = values.iterator();
+
+    // Replace existing values, if any.
+    while (keyValues.hasNext() && newValues.hasNext()) {
+      keyValues.next();
+      keyValues.set(newValues.next());
+    }
+
+    // Remove remaining old values, if any.
+    while (keyValues.hasNext()) {
+      keyValues.next();
+      keyValues.remove();
+    }
+
+    // Add remaining new values, if any.
+    while (newValues.hasNext()) {
+      keyValues.add(newValues.next());
+    }
+
+    return oldValues;
+  }
+
+  private List<V> getCopy(@ParametricNullness K key) {
+    return unmodifiableList(Lists.newArrayList(new ValueForKeyIterator(key)));
+  }
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>The returned list is immutable and implements {@link java.util.RandomAccess}.
+   */
+  @CanIgnoreReturnValue
+  @Override
+  public List<V> removeAll(@Nullable Object key) {
+    /*
+     * Safe because all we do is remove values for the key, not add them. (If we wanted to make sure
+     * to call getCopy and removeAllNodes only with a true K, then we could check containsKey first.
+     * But that check wouldn't eliminate the warnings.)
+     */
+    @SuppressWarnings({"unchecked", "nullness"})
+    K castKey = (K) key;
+    List<V> oldValues = getCopy(castKey);
+    removeAllNodes(castKey);
+    return oldValues;
+  }
+
+  @Override
+  public void clear() {
+    head = null;
+    tail = null;
+    keyToKeyList.clear();
+    size = 0;
+    modCount++;
+  }
+
+  // Views
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>If the multimap is modified while an iteration over the list is in progress (except through
+   * the iterator's own {@code add}, {@code set} or {@code remove} operations) the results of the
+   * iteration are undefined.
+   *
+   * <p>The returned list is not serializable and does not have random access.
+   */
+  @Override
+  public List<V> get(@ParametricNullness final K key) {
+    return new AbstractSequentialList<V>() {
+      @Override
+      public int size() {
+        KeyList<K, V> keyList = keyToKeyList.get(key);
+        return (keyList == null) ? 0 : keyList.count;
+      }
+
+      @Override
+      public ListIterator<V> listIterator(int index) {
+        return new ValueForKeyIterator(key, index);
+      }
+    };
+  }
+
+  @Override
+  Set<K> createKeySet() {
+    @WeakOuter
+    class KeySetImpl extends Sets.ImprovedAbstractSet<K> {
+      @Override
+      public int size() {
+        return keyToKeyList.size();
+      }
+
+      @Override
+      public Iterator<K> iterator() {
+        return new DistinctKeyIterator();
+      }
+
+      @Override
+      public boolean contains(@CheckForNull Object key) { // for performance
+        return containsKey(key);
+      }
+
+      @Override
+      public boolean remove(@CheckForNull Object o) { // for performance
+        return !LinkedListMultimap.this.removeAll(o).isEmpty();
+      }
+    }
+    return new KeySetImpl();
+  }
+
+  @Override
+  Multiset<K> createKeys() {
+    return new Multimaps.Keys<K, V>(this);
+  }
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>The iterator generated by the returned collection traverses the values in the order they
+   * were added to the multimap. Because the values may have duplicates and follow the insertion
+   * ordering, this method returns a {@link List}, instead of the {@link Collection} specified in
+   * the {@link ListMultimap} interface.
+   */
+  @Override
+  public List<V> values() {
+    return (List<V>) super.values();
+  }
+
+  @Override
+  List<V> createValues() {
+    @WeakOuter
+    class ValuesImpl extends AbstractSequentialList<V> {
+      @Override
+      public int size() {
+        return size;
+      }
+
+      @Override
+      public ListIterator<V> listIterator(int index) {
+        final NodeIterator nodeItr = new NodeIterator(index);
+        return new TransformedListIterator<Entry<K, V>, V>(nodeItr) {
+          @Override
+          @ParametricNullness
+          V transform(Entry<K, V> entry) {
+            return entry.getValue();
+          }
+
+          @Override
+          public void set(@ParametricNullness V value) {
+            nodeItr.setValue(value);
+          }
+        };
+      }
+    }
+    return new ValuesImpl();
+  }
+
+  /**
+   * {@inheritDoc}
+   *
+   * <p>The iterator generated by the returned collection traverses the entries in the order they
+   * were added to the multimap. Because the entries may have duplicates and follow the insertion
+   * ordering, this method returns a {@link List}, instead of the {@link Collection} specified in
+   * the {@link ListMultimap} interface.
+   *
+   * <p>An entry's {@link Entry#getKey} method always returns the same key, regardless of what
+   * happens subsequently. As long as the corresponding key-value mapping is not removed from the
+   * multimap, {@link Entry#getValue} returns the value from the multimap, which may change over
+   * time, and {@link Entry#setValue} modifies that value. Removing the mapping from the multimap
+   * does not alter the value returned by {@code getValue()}, though a subsequent {@code setValue()}
+   * call won't update the multimap but will lead to a revised value being returned by {@code
+   * getValue()}.
+   */
+  @Override
+  public List<Entry<K, V>> entries() {
+    return (List<Entry<K, V>>) super.entries();
+  }
+
+  @Override
+  List<Entry<K, V>> createEntries() {
+    @WeakOuter
+    class EntriesImpl extends AbstractSequentialList<Entry<K, V>> {
+      @Override
+      public int size() {
+        return size;
+      }
+
+      @Override
+      public ListIterator<Entry<K, V>> listIterator(int index) {
+        return new NodeIterator(index);
+      }
+
+      @Override
+      public void forEach(Consumer<? super Entry<K, V>> action) {
+        checkNotNull(action);
+        for (Node<K, V> node = head; node != null; node = node.next) {
+          action.accept(node);
+        }
+      }
+    }
+    return new EntriesImpl();
+  }
+
+  @Override
+  Iterator<Entry<K, V>> entryIterator() {
+    throw new AssertionError("should never be called");
+  }
+
+  @Override
+  Map<K, Collection<V>> createAsMap() {
+    return new Multimaps.AsMap<>(this);
+  }
+
+  /**
+   * @serialData the number of distinct keys, and then for each distinct key: the first key, the
+   *     number of values for that key, and the key's values, followed by successive keys and values
+   *     from the entries() ordering
+   */
+  @GwtIncompatible // java.io.ObjectOutputStream
+  private void writeObject(ObjectOutputStream stream) throws IOException {
+    stream.defaultWriteObject();
+    stream.writeInt(size());
+    for (Entry<K, V> entry : entries()) {
+      stream.writeObject(entry.getKey());
+      stream.writeObject(entry.getValue());
+    }
+  }
+
+  @GwtIncompatible // java.io.ObjectInputStream
+  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
+    stream.defaultReadObject();
+    keyToKeyList = Maps.newLinkedHashMap();
+    int size = stream.readInt();
+    for (int i = 0; i < size; i++) {
+      @SuppressWarnings("unchecked") // reading data stored by writeObject
+      K key = (K) stream.readObject();
+      @SuppressWarnings("unchecked") // reading data stored by writeObject
+      V value = (V) stream.readObject();
+      put(key, value);
+    }
+  }
+
+  @GwtIncompatible // java serialization not supported
+  private static final long serialVersionUID = 0;
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/MapsKeySet.java

@@ -0,0 +1,69 @@
+package org.xbib.datastructures.multi;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Objects;
+import java.util.function.Consumer;
+
+public class MapsKeySet<K extends Object, V extends Object> extends ImprovedAbstractSet<K> {
+    final Map<K, V> map;
+
+    MapsKeySet(Map<K, V> map) {
+        this.map = Objects.requireNonNull(map);
+    }
+
+    Map<K, V> map() {
+        return map;
+    }
+
+    @Override
+    public Iterator<K> iterator() {
+        return keyIterator(map().entrySet().iterator());
+    }
+
+    @Override
+    public void forEach(Consumer<? super K> action) {
+        Objects.requireNonNull(action);
+        // avoids entry allocation for those maps that allocate entries on iteration
+        map.forEach((k, v) -> action.accept(k));
+    }
+
+    @Override
+    public int size() {
+        return map().size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return map().isEmpty();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        return map().containsKey(o);
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        if (contains(o)) {
+            map().remove(o);
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public void clear() {
+        map().clear();
+    }
+
+    private static <K extends Object, V extends Object> Iterator<K> keyIterator(
+            Iterator<Map.Entry<K, V>> entryIterator) {
+        return new TransformedIterator<Map.Entry<K, V>, K>(entryIterator) {
+            @Override
+            K transform(Map.Entry<K, V> entry) {
+                return entry.getKey();
+            }
+        };
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/MultimapBuilder.java

@@ -0,0 +1,461 @@
+package org.xbib.datastructures.multi;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.EnumMap;
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeMap;
+import java.util.TreeSet;
+import java.util.function.Supplier;
+import org.xbib.datastructures.api.ListMultimap;
+import org.xbib.datastructures.api.Multimap;
+import org.xbib.datastructures.api.SetMultimap;
+import org.xbib.datastructures.api.SortedSetMultimap;
+import org.xbib.datastructures.immutable.order.Ordering;
+
+/**
+ * A builder for a multimap implementation that allows customization of the backing map and value
+ * collection implementations used in a particular multimap.
+ *
+ * <p>This can be used to easily configure multimap data structure implementations not provided
+ * explicitly in {@code com.google.common.collect}, for example:
+ *
+ * <pre>{@code
+ * ListMultimap<String, Integer> treeListMultimap =
+ *     MultimapBuilder.treeKeys().arrayListValues().build();
+ * SetMultimap<Integer, MyEnum> hashEnumMultimap =
+ *     MultimapBuilder.hashKeys().enumSetValues(MyEnum.class).build();
+ * }</pre>
+ *
+ * <p>{@code MultimapBuilder} instances are immutable. Invoking a configuration method has no effect
+ * on the receiving instance; you must store and use the new builder instance it returns instead.
+ *
+ * <p>The generated multimaps are serializable if the key and value types are serializable, unless
+ * stated otherwise in one of the configuration methods.
+ *
+ * @author Louis Wasserman
+ * @param <K0> An upper bound on the key type of the generated multimap.
+ * @param <V0> An upper bound on the value type of the generated multimap.
+ */
+public abstract class MultimapBuilder<K0 extends Object, V0 extends Object> {
+    /*
+     * Leaving K and V as upper bounds rather than the actual key and value types allows type
+     * parameters to be left implicit more often. CacheBuilder uses the same technique.
+     */
+
+    private MultimapBuilder() {}
+
+    private static final int DEFAULT_EXPECTED_KEYS = 8;
+
+    /** Uses a hash table to map keys to value collections. */
+    public static MultimapBuilderWithKeys<Object> hashKeys() {
+        return hashKeys(DEFAULT_EXPECTED_KEYS);
+    }
+
+    /**
+     * Uses a hash table to map keys to value collections, initialized to expect the specified number
+     * of keys.
+     *
+     * @throws IllegalArgumentException if {@code expectedKeys < 0}
+     */
+    public static MultimapBuilderWithKeys<Object> hashKeys(int expectedKeys) {
+        checkNonnegative(expectedKeys, "expectedKeys");
+        return new MultimapBuilderWithKeys<Object>() {
+            @Override
+            <K extends Object, V extends Object> Map<K, Collection<V>> createMap() {
+                return new HashMap(expectedKeys);
+            }
+        };
+    }
+
+    /**
+     * Uses a hash table to map keys to value collections.
+     *
+     * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
+     * Multimap#asMap()} will iterate through the keys in the order that they were first added to the
+     * multimap, save that if all values associated with a key are removed and then the key is added
+     * back into the multimap, that key will come last in the key iteration order.
+     */
+    public static MultimapBuilderWithKeys<Object> linkedHashKeys() {
+        return linkedHashKeys(DEFAULT_EXPECTED_KEYS);
+    }
+
+    /**
+     * Uses an hash table to map keys to value collections, initialized to expect the specified number
+     * of keys.
+     *
+     * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
+     * Multimap#asMap()} will iterate through the keys in the order that they were first added to the
+     * multimap, save that if all values associated with a key are removed and then the key is added
+     * back into the multimap, that key will come last in the key iteration order.
+     */
+    public static MultimapBuilderWithKeys<Object> linkedHashKeys(int expectedKeys) {
+        checkNonnegative(expectedKeys, "expectedKeys");
+        return new MultimapBuilderWithKeys<Object>() {
+            @Override
+            <K extends Object, V extends Object> Map<K, Collection<V>> createMap() {
+                return new LinkedHashMap<>(expectedKeys);
+            }
+        };
+    }
+
+    /**
+     * Uses a naturally-ordered {@link TreeMap} to map keys to value collections.
+     *
+     * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
+     * Multimap#asMap()} will iterate through the keys in sorted order.
+     *
+     * <p>For all multimaps generated by the resulting builder, the {@link Multimap#keySet()} can be
+     * safely cast to a {@link SortedSet}, and the {@link Multimap#asMap()} can safely be
+     * cast to a {@link java.util.SortedMap}.
+     */
+    @SuppressWarnings("rawtypes")
+    public static MultimapBuilderWithKeys<Comparable> treeKeys() {
+        return treeKeys(Ordering.natural());
+    }
+
+    /**
+     * Uses a {@link TreeMap} sorted by the specified comparator to map keys to value collections.
+     *
+     * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
+     * Multimap#asMap()} will iterate through the keys in sorted order.
+     *
+     * <p>For all multimaps generated by the resulting builder, the {@link Multimap#keySet()} can be
+     * safely cast to a {@link SortedSet}, and the {@link Multimap#asMap()} can safely be
+     * cast to a {@link java.util.SortedMap}.
+     *
+     * <p>Multimaps generated by the resulting builder will not be serializable if {@code comparator}
+     * is not serializable.
+     */
+    public static <K0 extends Object> MultimapBuilderWithKeys<K0> treeKeys(
+            Comparator<K0> comparator) {
+        Objects.requireNonNull(comparator);
+        return new MultimapBuilderWithKeys<K0>() {
+            @Override
+            <K extends K0, V extends Object> Map<K, Collection<V>> createMap() {
+                return new TreeMap<>(comparator);
+            }
+        };
+    }
+
+    /**
+     * Uses an {@link EnumMap} to map keys to value collections.
+     */
+    public static <K0 extends Enum<K0>> MultimapBuilderWithKeys<K0> enumKeys(Class<K0> keyClass) {
+        Objects.requireNonNull(keyClass);
+        return new MultimapBuilderWithKeys<K0>() {
+            @SuppressWarnings("unchecked")
+            @Override
+            <K extends K0, V extends Object> Map<K, Collection<V>> createMap() {
+                // K must actually be K0, since enums are effectively final
+                // (their subclasses are inaccessible)
+                return (Map<K, Collection<V>>) new EnumMap<K0, Collection<V>>(keyClass);
+            }
+        };
+    }
+
+    private static final class ArrayListSupplier<V extends Object>
+            implements Supplier<List<V>>, Serializable {
+        private final int expectedValuesPerKey;
+
+        ArrayListSupplier(int expectedValuesPerKey) {
+            this.expectedValuesPerKey = checkNonnegative(expectedValuesPerKey, "expectedValuesPerKey");
+        }
+
+        @Override
+        public List<V> get() {
+            return new ArrayList<>(expectedValuesPerKey);
+        }
+    }
+
+    private enum LinkedListSupplier implements Supplier<List<?>> {
+        INSTANCE;
+
+        public static <V extends Object> Supplier<List<V>> instance() {
+            // Each call generates a fresh LinkedList, which can serve as a List<V> for any V.
+            @SuppressWarnings({"rawtypes", "unchecked"})
+            Supplier<List<V>> result = (Supplier) INSTANCE;
+            return result;
+        }
+
+        @Override
+        public List<?> get() {
+            return new LinkedList<>();
+        }
+    }
+
+    private static final class HashSetSupplier<V extends Object>
+            implements Supplier<Set<V>>, Serializable {
+        private final int expectedValuesPerKey;
+
+        HashSetSupplier(int expectedValuesPerKey) {
+            this.expectedValuesPerKey = checkNonnegative(expectedValuesPerKey, "expectedValuesPerKey");
+        }
+
+        @Override
+        public Set<V> get() {
+            return new HashSet<>(expectedValuesPerKey);
+        }
+    }
+
+    private static final class LinkedHashSetSupplier<V extends Object>
+            implements Supplier<Set<V>>, Serializable {
+        private final int expectedValuesPerKey;
+
+        LinkedHashSetSupplier(int expectedValuesPerKey) {
+            this.expectedValuesPerKey = checkNonnegative(expectedValuesPerKey, "expectedValuesPerKey");
+        }
+
+        @Override
+        public Set<V> get() {
+            return new LinkedHashSet(expectedValuesPerKey);
+        }
+    }
+
+    private static final class TreeSetSupplier<V extends Object>
+            implements Supplier<SortedSet<V>>, Serializable {
+        private final Comparator<? super V> comparator;
+
+        TreeSetSupplier(Comparator<? super V> comparator) {
+            this.comparator = Objects.requireNonNull(comparator);
+        }
+
+        @Override
+        public SortedSet<V> get() {
+            return new TreeSet<>(comparator);
+        }
+    }
+
+    private static final class EnumSetSupplier<V extends Enum<V>>
+            implements Supplier<Set<V>>, Serializable {
+        private final Class<V> clazz;
+
+        EnumSetSupplier(Class<V> clazz) {
+            this.clazz = Objects.requireNonNull(clazz);
+        }
+
+        @Override
+        public Set<V> get() {
+            return EnumSet.noneOf(clazz);
+        }
+    }
+
+    /**
+     * An intermediate stage in a {@link MultimapBuilder} in which the key-value collection map
+     * implementation has been specified, but the value collection implementation has not.
+     *
+     * @param <K0> The upper bound on the key type of the generated multimap.
+     * @since 16.0
+     */
+    public abstract static class MultimapBuilderWithKeys<K0 extends Object> {
+
+        private static final int DEFAULT_EXPECTED_VALUES_PER_KEY = 2;
+
+        MultimapBuilderWithKeys() {}
+
+        abstract <K extends K0, V extends Object> Map<K, Collection<V>> createMap();
+
+        /** Uses an {@link ArrayList} to store value collections. */
+        public ListMultimapBuilder<K0, Object> arrayListValues() {
+            return arrayListValues(DEFAULT_EXPECTED_VALUES_PER_KEY);
+        }
+
+        /**
+         * Uses an {@link ArrayList} to store value collections, initialized to expect the specified
+         * number of values per key.
+         *
+         * @throws IllegalArgumentException if {@code expectedValuesPerKey < 0}
+         */
+        public ListMultimapBuilder<K0, Object> arrayListValues(int expectedValuesPerKey) {
+            checkNonnegative(expectedValuesPerKey, "expectedValuesPerKey");
+            return new ListMultimapBuilder<K0, Object>() {
+                @Override
+                public <K extends K0, V extends Object> ListMultimap<K, V> build() {
+                    return Multimaps.newListMultimap(
+                            MultimapBuilderWithKeys.this.<K, V>createMap(),
+                            new ArrayListSupplier<V>(expectedValuesPerKey));
+                }
+            };
+        }
+
+        /** Uses a {@link LinkedList} to store value collections. */
+        public ListMultimapBuilder<K0, Object> linkedListValues() {
+            return new ListMultimapBuilder<K0, Object>() {
+                @Override
+                public <K extends K0, V extends Object> ListMultimap<K, V> build() {
+                    return Multimaps.newListMultimap(
+                            MultimapBuilderWithKeys.this.<K, V>createMap(), LinkedListSupplier.<V>instance());
+                }
+            };
+        }
+
+        /** Uses a hash-based {@code Set} to store value collections. */
+        public SetMultimapBuilder<K0, Object> hashSetValues() {
+            return hashSetValues(DEFAULT_EXPECTED_VALUES_PER_KEY);
+        }
+
+        /**
+         * Uses a hash-based {@code Set} to store value collections, initialized to expect the specified
+         * number of values per key.
+         *
+         * @throws IllegalArgumentException if {@code expectedValuesPerKey < 0}
+         */
+        public SetMultimapBuilder<K0, Object> hashSetValues(int expectedValuesPerKey) {
+            checkNonnegative(expectedValuesPerKey, "expectedValuesPerKey");
+            return new SetMultimapBuilder<K0, Object>() {
+                @Override
+                public <K extends K0, V extends Object> SetMultimap<K, V> build() {
+                    return Multimaps.newSetMultimap(
+                            MultimapBuilderWithKeys.this.<K, V>createMap(),
+                            new HashSetSupplier<V>(expectedValuesPerKey));
+                }
+            };
+        }
+
+        /** Uses an insertion-ordered hash-based {@code Set} to store value collections. */
+        public SetMultimapBuilder<K0, Object> linkedHashSetValues() {
+            return linkedHashSetValues(DEFAULT_EXPECTED_VALUES_PER_KEY);
+        }
+
+        /**
+         * Uses an insertion-ordered hash-based {@code Set} to store value collections, initialized to
+         * expect the specified number of values per key.
+         *
+         * @throws IllegalArgumentException if {@code expectedValuesPerKey < 0}
+         */
+        public SetMultimapBuilder<K0, Object> linkedHashSetValues(int expectedValuesPerKey) {
+            checkNonnegative(expectedValuesPerKey, "expectedValuesPerKey");
+            return new SetMultimapBuilder<K0, Object>() {
+                @Override
+                public <K extends K0, V extends Object> SetMultimap<K, V> build() {
+                    return Multimaps.newSetMultimap(
+                            MultimapBuilderWithKeys.this.<K, V>createMap(),
+                            new LinkedHashSetSupplier<V>(expectedValuesPerKey));
+                }
+            };
+        }
+
+        /** Uses a naturally-ordered {@link TreeSet} to store value collections. */
+        @SuppressWarnings("rawtypes")
+        public SortedSetMultimapBuilder<K0, Comparable> treeSetValues() {
+            return treeSetValues(Ordering.natural());
+        }
+
+        /**
+         * Uses a {@link TreeSet} ordered by the specified comparator to store value collections.
+         *
+         * <p>Multimaps generated by the resulting builder will not be serializable if {@code
+         * comparator} is not serializable.
+         */
+        public <V0 extends Object> SortedSetMultimapBuilder<K0, V0> treeSetValues(
+                Comparator<V0> comparator) {
+            Objects.requireNonNull(comparator, "comparator");
+            return new SortedSetMultimapBuilder<K0, V0>() {
+                @Override
+                public <K extends K0, V extends V0> SortedSetMultimap<K, V> build() {
+                    return Multimaps.newSortedSetMultimap(
+                            MultimapBuilderWithKeys.this.<K, V>createMap(), new TreeSetSupplier<V>(comparator));
+                }
+            };
+        }
+
+        /** Uses an {@link EnumSet} to store value collections. */
+        public <V0 extends Enum<V0>> SetMultimapBuilder<K0, V0> enumSetValues(Class<V0> valueClass) {
+            Objects.requireNonNull(valueClass, "valueClass");
+            return new SetMultimapBuilder<K0, V0>() {
+                @Override
+                public <K extends K0, V extends V0> SetMultimap<K, V> build() {
+                    // V must actually be V0, since enums are effectively final
+                    // (their subclasses are inaccessible)
+                    @SuppressWarnings({"unchecked", "rawtypes"})
+                    Supplier<Set<V>> factory = (Supplier) new EnumSetSupplier<V0>(valueClass);
+                    return Multimaps.newSetMultimap(MultimapBuilderWithKeys.this.<K, V>createMap(), factory);
+                }
+            };
+        }
+    }
+
+    /** Returns a new, empty {@code Multimap} with the specified implementation. */
+    public abstract <K extends K0, V extends V0> Multimap<K, V> build();
+
+    /**
+     * Returns a {@code Multimap} with the specified implementation, initialized with the entries of
+     * {@code multimap}.
+     */
+    public <K extends K0, V extends V0> Multimap<K, V> build(
+            Multimap<? extends K, ? extends V> multimap) {
+        Multimap<K, V> result = build();
+        result.putAll(multimap);
+        return result;
+    }
+
+    /**
+     * A specialization of {@link MultimapBuilder} that generates {@link ListMultimap} instances.
+     */
+    public abstract static class ListMultimapBuilder<
+            K0 extends Object, V0 extends Object>
+            extends MultimapBuilder<K0, V0> {
+        ListMultimapBuilder() {}
+
+        @Override
+        public abstract <K extends K0, V extends V0> ListMultimap<K, V> build();
+
+        @Override
+        public <K extends K0, V extends V0> ListMultimap<K, V> build(
+                Multimap<? extends K, ? extends V> multimap) {
+            return (ListMultimap<K, V>) super.build(multimap);
+        }
+    }
+
+    /**
+     * A specialization of {@link MultimapBuilder} that generates {@link SetMultimap} instances.
+     *
+     * @since 16.0
+     */
+    public abstract static class SetMultimapBuilder<
+            K0 extends Object, V0 extends Object>
+            extends MultimapBuilder<K0, V0> {
+        SetMultimapBuilder() {}
+
+        @Override
+        public abstract <K extends K0, V extends V0> SetMultimap<K, V> build();
+
+        @Override
+        public <K extends K0, V extends V0> SetMultimap<K, V> build(
+                Multimap<? extends K, ? extends V> multimap) {
+            return (SetMultimap<K, V>) super.build(multimap);
+        }
+    }
+
+    /**
+     * A specialization of {@link MultimapBuilder} that generates {@link SortedSetMultimap} instances.
+     *
+     * @since 16.0
+     */
+    public abstract static class SortedSetMultimapBuilder<
+            K0 extends Object, V0 extends Object>
+            extends SetMultimapBuilder<K0, V0> {
+        SortedSetMultimapBuilder() {}
+
+        @Override
+        public abstract <K extends K0, V extends V0> SortedSetMultimap<K, V> build();
+
+        @Override
+        public <K extends K0, V extends V0> SortedSetMultimap<K, V> build(
+                Multimap<? extends K, ? extends V> multimap) {
+            return (SortedSetMultimap<K, V>) super.build(multimap);
+        }
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/MultimapsEntries.java

@@ -0,0 +1,39 @@
+package org.xbib.datastructures.multi;
+
+import java.util.AbstractCollection;
+import java.util.Map;
+import org.xbib.datastructures.api.Multimap;
+
+/** A skeleton implementation of {@link Multimap#entries()}. */
+abstract class MultimapsEntries<K extends Object, V extends Object>
+        extends AbstractCollection<Map.Entry<K, V>> {
+    abstract Multimap<K, V> multimap();
+
+    @Override
+    public int size() {
+        return multimap().size();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        if (o instanceof Map.Entry) {
+            Map.Entry<?, ?> entry = (Map.Entry<?, ?>) o;
+            return multimap().containsEntry(entry.getKey(), entry.getValue());
+        }
+        return false;
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        if (o instanceof Map.Entry) {
+            Map.Entry<?, ?> entry = (Map.Entry<?, ?>) o;
+            return multimap().remove(entry.getKey(), entry.getValue());
+        }
+        return false;
+    }
+
+    @Override
+    public void clear() {
+        multimap().clear();
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/MultisetsAbstractEntry.java

@@ -0,0 +1,47 @@
+package org.xbib.datastructures.multi;
+
+import java.util.Objects;
+import org.xbib.datastructures.api.Multiset;
+
+/**
+ * Implementation of the {@code equals}, {@code hashCode}, and {@code toString} methods of {@link
+ * Multiset.Entry}.
+ */
+public abstract class MultisetsAbstractEntry<E extends Object> implements Multiset.Entry<E> {
+    /**
+     * Indicates whether an object equals this entry, following the behavior specified in {@link
+     * Multiset.Entry#equals}.
+     */
+    @Override
+    public boolean equals(Object object) {
+        if (object instanceof Multiset.Entry) {
+            Multiset.Entry<?> that = (Multiset.Entry<?>) object;
+            return this.getCount() == that.getCount()
+                    && Objects.equals(this.getElement(), that.getElement());
+        }
+        return false;
+    }
+
+    /**
+     * Return this entry's hash code, following the behavior specified in {@link
+     * Multiset.Entry#hashCode}.
+     */
+    @Override
+    public int hashCode() {
+        E e = getElement();
+        return ((e == null) ? 0 : e.hashCode()) ^ getCount();
+    }
+
+    /**
+     * Returns a string representation of this multiset entry. The string representation consists of
+     * the associated element if the associated count is one, and otherwise the associated element
+     * followed by the characters " x " (space, x and space) followed by the count. Elements and
+     * counts are converted to strings as by {@code String.valueOf}.
+     */
+    @Override
+    public String toString() {
+        String text = String.valueOf(getElement());
+        int n = getCount();
+        return (n == 1) ? text : (text + " x " + n);
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/MultisetsImmutableEntry.java

@@ -0,0 +1,33 @@
+package org.xbib.datastructures.multi;
+
+import java.io.Serializable;
+
+public class MultisetsImmutableEntry<E extends Object> extends MultisetsAbstractEntry<E>
+        implements Serializable {
+    private final E element;
+    private final int count;
+
+    MultisetsImmutableEntry(E element, int count) {
+        this.element = element;
+        this.count = count;
+        if (count < 0) {
+            throw new IllegalArgumentException("count");
+        }
+    }
+
+    @Override
+    public final E getElement() {
+        return element;
+    }
+
+    @Override
+    public final int getCount() {
+        return count;
+    }
+
+    public MultisetsImmutableEntry<E> nextInBucket() {
+        return null;
+    }
+
+    private static final long serialVersionUID = 0;
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/Serialization.java

@@ -0,0 +1,204 @@
+package org.xbib.datastructures.multi;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.lang.reflect.Field;
+import java.util.Collection;
+import java.util.Map;
+import org.xbib.datastructures.api.Multimap;
+import org.xbib.datastructures.api.Multiset;
+
+/**
+ * Provides static methods for serializing collection classes.
+ *
+ * <p>This class assists the implementation of collection classes. Do not use this class to
+ * serialize collections that are defined elsewhere.
+ */
+final class Serialization {
+    private Serialization() {}
+
+    /**
+     * Reads a count corresponding to a serialized map, multiset, or multimap. It returns the size of
+     * a map serialized by {@link #writeMap(Map, ObjectOutputStream)}, the number of distinct elements
+     * in a multiset serialized by {@link #writeMultiset(Multiset, ObjectOutputStream)}, or the number
+     * of distinct keys in a multimap serialized by {@link #writeMultimap(Multimap,
+     * ObjectOutputStream)}.
+     */
+    static int readCount(ObjectInputStream stream) throws IOException {
+        return stream.readInt();
+    }
+
+    /**
+     * Stores the contents of a map in an output stream, as part of serialization. It does not support
+     * concurrent maps whose content may change while the method is running.
+     *
+     * <p>The serialized output consists of the number of entries, first key, first value, second key,
+     * second value, and so on.
+     */
+    static <K extends Object, V extends Object> void writeMap(
+            Map<K, V> map, ObjectOutputStream stream) throws IOException {
+        stream.writeInt(map.size());
+        for (Map.Entry<K, V> entry : map.entrySet()) {
+            stream.writeObject(entry.getKey());
+            stream.writeObject(entry.getValue());
+        }
+    }
+
+    /**
+     * Populates a map by reading an input stream, as part of deserialization. See {@link #writeMap}
+     * for the data format.
+     */
+    static <K extends Object, V extends Object> void populateMap(
+            Map<K, V> map, ObjectInputStream stream) throws IOException, ClassNotFoundException {
+        int size = stream.readInt();
+        populateMap(map, stream, size);
+    }
+
+    /**
+     * Populates a map by reading an input stream, as part of deserialization. See {@link #writeMap}
+     * for the data format. The size is determined by a prior call to {@link #readCount}.
+     */
+    static <K extends Object, V extends Object> void populateMap(
+            Map<K, V> map, ObjectInputStream stream, int size)
+            throws IOException, ClassNotFoundException {
+        for (int i = 0; i < size; i++) {
+            @SuppressWarnings("unchecked") // reading data stored by writeMap
+            K key = (K) stream.readObject();
+            @SuppressWarnings("unchecked") // reading data stored by writeMap
+            V value = (V) stream.readObject();
+            map.put(key, value);
+        }
+    }
+
+    /**
+     * Stores the contents of a multiset in an output stream, as part of serialization. It does not
+     * support concurrent multisets whose content may change while the method is running.
+     *
+     * <p>The serialized output consists of the number of distinct elements, the first element, its
+     * count, the second element, its count, and so on.
+     */
+    static <E extends Object> void writeMultiset(
+            Multiset<E> multiset, ObjectOutputStream stream) throws IOException {
+        int entryCount = multiset.entrySet().size();
+        stream.writeInt(entryCount);
+        for (Multiset.Entry<E> entry : multiset.entrySet()) {
+            stream.writeObject(entry.getElement());
+            stream.writeInt(entry.getCount());
+        }
+    }
+
+    /**
+     * Populates a multiset by reading an input stream, as part of deserialization. See {@link
+     * #writeMultiset} for the data format.
+     */
+    static <E extends Object> void populateMultiset(
+            Multiset<E> multiset, ObjectInputStream stream) throws IOException, ClassNotFoundException {
+        int distinctElements = stream.readInt();
+        populateMultiset(multiset, stream, distinctElements);
+    }
+
+    /**
+     * Populates a multiset by reading an input stream, as part of deserialization. See {@link
+     * #writeMultiset} for the data format. The number of distinct elements is determined by a prior
+     * call to {@link #readCount}.
+     */
+    static <E extends Object> void populateMultiset(
+            Multiset<E> multiset, ObjectInputStream stream, int distinctElements)
+            throws IOException, ClassNotFoundException {
+        for (int i = 0; i < distinctElements; i++) {
+            @SuppressWarnings("unchecked") // reading data stored by writeMultiset
+            E element = (E) stream.readObject();
+            int count = stream.readInt();
+            multiset.add(element, count);
+        }
+    }
+
+    /**
+     * Stores the contents of a multimap in an output stream, as part of serialization. It does not
+     * support concurrent multimaps whose content may change while the method is running. The {@link
+     * Multimap#asMap} view determines the ordering in which data is written to the stream.
+     *
+     * <p>The serialized output consists of the number of distinct keys, and then for each distinct
+     * key: the key, the number of values for that key, and the key's values.
+     */
+    static <K extends Object, V extends Object> void writeMultimap(
+            Multimap<K, V> multimap, ObjectOutputStream stream) throws IOException {
+        stream.writeInt(multimap.asMap().size());
+        for (Map.Entry<K, Collection<V>> entry : multimap.asMap().entrySet()) {
+            stream.writeObject(entry.getKey());
+            stream.writeInt(entry.getValue().size());
+            for (V value : entry.getValue()) {
+                stream.writeObject(value);
+            }
+        }
+    }
+
+    /**
+     * Populates a multimap by reading an input stream, as part of deserialization. See {@link
+     * #writeMultimap} for the data format.
+     */
+    static <K extends Object, V extends Object> void populateMultimap(
+            Multimap<K, V> multimap, ObjectInputStream stream)
+            throws IOException, ClassNotFoundException {
+        int distinctKeys = stream.readInt();
+        populateMultimap(multimap, stream, distinctKeys);
+    }
+
+    /**
+     * Populates a multimap by reading an input stream, as part of deserialization. See {@link
+     * #writeMultimap} for the data format. The number of distinct keys is determined by a prior call
+     * to {@link #readCount}.
+     */
+    static <K extends Object, V extends Object> void populateMultimap(
+            Multimap<K, V> multimap, ObjectInputStream stream, int distinctKeys)
+            throws IOException, ClassNotFoundException {
+        for (int i = 0; i < distinctKeys; i++) {
+            @SuppressWarnings("unchecked") // reading data stored by writeMultimap
+            K key = (K) stream.readObject();
+            Collection<V> values = multimap.get(key);
+            int valueCount = stream.readInt();
+            for (int j = 0; j < valueCount; j++) {
+                @SuppressWarnings("unchecked") // reading data stored by writeMultimap
+                V value = (V) stream.readObject();
+                values.add(value);
+            }
+        }
+    }
+
+    // Secret sauce for setting final fields; don't make it public.
+    static <T> FieldSetter<T> getFieldSetter(Class<T> clazz, String fieldName) {
+        try {
+            Field field = clazz.getDeclaredField(fieldName);
+            return new FieldSetter<>(field);
+        } catch (NoSuchFieldException e) {
+            throw new AssertionError(e); // programmer error
+        }
+    }
+
+    // Secret sauce for setting final fields; don't make it public.
+    static final class FieldSetter<T> {
+        private final Field field;
+
+        private FieldSetter(Field field) {
+            this.field = field;
+            field.setAccessible(true);
+        }
+
+        void set(T instance, Object value) {
+            try {
+                field.set(instance, value);
+            } catch (IllegalAccessException impossible) {
+                throw new AssertionError(impossible);
+            }
+        }
+
+        void set(T instance, int value) {
+            try {
+                field.set(instance, value);
+            } catch (IllegalAccessException impossible) {
+                throw new AssertionError(impossible);
+            }
+        }
+    }
+}

datastructures-multi/src/main/java/org/xbib/datastructures/multi/TransformedIterator.java

@@ -0,0 +1,33 @@
+package org.xbib.datastructures.multi;
+
+import java.util.Iterator;
+import java.util.Objects;
+
+/**
+ * An iterator that transforms a backing iterator; for internal use.
+ */
+abstract class TransformedIterator<F extends Object, T extends Object>
+        implements Iterator<T> {
+    final Iterator<? extends F> backingIterator;
+
+    TransformedIterator(Iterator<? extends F> backingIterator) {
+        this.backingIterator = Objects.requireNonNull(backingIterator);
+    }
+
+    abstract T transform(F from);
+
+    @Override
+    public final boolean hasNext() {
+        return backingIterator.hasNext();
+    }
+
+    @Override
+    public final T next() {
+        return transform(backingIterator.next());
+    }
+
+    @Override
+    public final void remove() {
+        backingIterator.remove();
+    }
+}

datastructures-validation/build.gradle

@@ -2,9 +2,3 @@ dependencies {
     testImplementation testLibs.assertj
     testImplementation testLibs.compile.testing
 }
-
-test {
-    jvmArgs '--add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED',
-            '--add-exports=jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED',
-            '--add-exports=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED'
-}

datastructures-xslx/src/main/java/com/incesoft/tools/excel/support/CellFormat.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.support;
 
 public class CellFormat {
 	public CellFormat() {

datastructures-xslx/src/main/java/com/incesoft/tools/excel/support/XLSReaderSupport.java

@@ -1,13 +1,16 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.support;
 
 import java.io.File;
 import java.text.SimpleDateFormat;
 
-import org.xbib.datastructures.xslx.jxl.Cell;
-import org.xbib.datastructures.xslx.jxl.CellType;
-import org.xbib.datastructures.xslx.jxl.DateCell;
-import org.xbib.datastructures.xslx.jxl.Sheet;
-import org.xbib.datastructures.xslx.jxl.Workbook;
+import org.xbib.datastructures.xslx.ExcelRowIterator;
+import org.xbib.datastructures.xslx.ReaderSupport;
+
+import jxl.Cell;
+import jxl.CellType;
+import jxl.DateCell;
+import jxl.Sheet;
+import jxl.Workbook;
 
 public class XLSReaderSupport extends ReaderSupport {
 

datastructures-xslx/src/main/java/com/incesoft/tools/excel/support/XLSWriterSupport.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.support;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -7,16 +7,18 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import org.xbib.datastructures.xslx.jxl.Workbook;
-import org.xbib.datastructures.xslx.jxl.format.Colour;
-import org.xbib.datastructures.xslx.jxl.format.RGB;
-import org.xbib.datastructures.xslx.jxl.write.Label;
-import org.xbib.datastructures.xslx.jxl.write.WritableCell;
-import org.xbib.datastructures.xslx.jxl.write.WritableCellFormat;
-import org.xbib.datastructures.xslx.jxl.write.WritableFont;
-import org.xbib.datastructures.xslx.jxl.write.WritableSheet;
-import org.xbib.datastructures.xslx.jxl.write.WritableWorkbook;
-import org.xbib.datastructures.xslx.jxl.write.WriteException;
+import jxl.Workbook;
+import jxl.format.Colour;
+import jxl.format.RGB;
+import jxl.write.Label;
+import jxl.write.WritableCell;
+import jxl.write.WritableCellFormat;
+import jxl.write.WritableFont;
+import jxl.write.WritableSheet;
+import jxl.write.WritableWorkbook;
+import jxl.write.WriteException;
+
+import org.xbib.datastructures.xslx.WriterSupport;
 
 public class XLSWriterSupport extends WriterSupport {
 	WritableSheet sheet;

datastructures-xslx/src/main/java/com/incesoft/tools/excel/support/XLSXReaderSupport.java

@@ -1,11 +1,13 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.support;
 
 import java.io.File;
-import java.io.IOException;
 
-import org.xbib.datastructures.xslx.Sheet.SheetRowReader;
-
-import javax.xml.stream.XMLStreamException;
+import org.xbib.datastructures.xslx.ExcelRowIterator;
+import org.xbib.datastructures.xslx.ReaderSupport;
+import com.incesoft.tools.excel.xlsx.Cell;
+import com.incesoft.tools.excel.xlsx.Sheet;
+import com.incesoft.tools.excel.xlsx.SimpleXLSXWorkbook;
+import com.incesoft.tools.excel.xlsx.Sheet.SheetRowReader;
 
 public class XLSXReaderSupport extends ReaderSupport {
 
@@ -31,7 +33,7 @@ public class XLSXReaderSupport extends ReaderSupport {
 					|| curRow[col] == null)
 				return null;
 			String v = curRow[col].getValue();
-			return v == null || v.trim().isEmpty() ? null : v.trim();
+			return v == null || v.trim().length() == 0 ? null : v.trim();
 		}
 
 		public int getRowPos() {
@@ -44,7 +46,7 @@ public class XLSXReaderSupport extends ReaderSupport {
 
 		SheetRowReader reader;
 
-		public void init() throws IOException {
+		public void init() {
 			reader = sheet.newReader();
 		}
 
@@ -83,14 +85,14 @@ public class XLSXReaderSupport extends ReaderSupport {
 
 		int rowPos = -1;
 
-		public void init() throws XMLStreamException, IOException {
+		public void init() {
 			currentSheetRowCount = sheet.getRowCount();
 		}
 
 		public boolean nextRow() {
 			rowPos++;
-			if (rowPos == currentSheetRowCount) {
-				return false;
+			if (rowPos == currentSheetRowCount) {// 当读取最后一行,如果当前读取的是当前sheet的最后一行
+				return false;// 所有记录里面的最后一行
 			}
 			return true;
 		}
@@ -99,7 +101,7 @@ public class XLSXReaderSupport extends ReaderSupport {
 			if (col < 0)
 				return null;
 			String v = sheet.getCellValue(rowPos, col);
-			return v == null || v.trim().isEmpty() ? null : v.trim();
+			return v == null || v.trim().length() == 0 ? null : v.trim();
 		}
 
 		public byte getSheetIndex() {
@@ -136,7 +138,7 @@ public class XLSXReaderSupport extends ReaderSupport {
 		}
 	}
 
-	public ExcelRowIterator rowIterator() throws XMLStreamException, IOException {
+	public ExcelRowIterator rowIterator() {
 		ExcelRowIterator iterator = lazy ? new LazyXLSXObjectIterator()
 				: new XLSXObjectIterator();
 		iterator.init();

datastructures-xslx/src/main/java/com/incesoft/tools/excel/support/XLSXWriterSupport.java

@@ -1,15 +1,25 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.support;
 
-import javax.xml.stream.XMLStreamException;
+import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 
+import org.xbib.datastructures.xslx.WriterSupport;
+import com.incesoft.tools.excel.xlsx.CellStyle;
+import com.incesoft.tools.excel.xlsx.Fill;
+import com.incesoft.tools.excel.xlsx.Font;
+import com.incesoft.tools.excel.xlsx.Sheet;
+import com.incesoft.tools.excel.xlsx.SimpleXLSXWorkbook;
+
 public class XLSXWriterSupport extends WriterSupport {
 	SimpleXLSXWorkbook workbook;
 
 	public void open() {
-		workbook = new SimpleXLSXWorkbook();
+		if (getClass().getResource("/empty.xlsx") == null) {
+			throw new IllegalStateException("no empty.xlsx found in classpath");
+		}
+		workbook = new SimpleXLSXWorkbook(new File(getClass().getResource("/empty.xlsx").getFile()));
 	}
 
 	Sheet sheet;
@@ -18,17 +28,17 @@ public class XLSXWriterSupport extends WriterSupport {
 		return Integer.MAX_VALUE / 2;
 	}
 
-	public void writeRow(String[] rowData) throws XMLStreamException, IOException {
+	public void writeRow(String[] rowData) {
 		writeRow(rowData, null);
 	}
 
-	public void writeRow(String[] rowData, CellFormat[] formats) throws XMLStreamException, IOException {
+	public void writeRow(String[] rowData, CellFormat[] formats) {
 		for (int col = 0; col < rowData.length; col++) {
 			String string = rowData[col];
 			if (string == null)
 				continue;
 			CellFormat format = null;
-			if (formats != null) {
+			if (formats != null && formats.length > 0) {
 				for (CellFormat cellFormat : formats) {
 					if (cellFormat != null && cellFormat.getCellIndex() == col) {
 						format = cellFormat;
@@ -82,7 +92,7 @@ public class XLSXWriterSupport extends WriterSupport {
 		}
 	}
 
-	public void createNewSheet() throws IOException {
+	public void createNewSheet() {
 		if (sheetIndex > 0) {
 			throw new IllegalStateException("only one sheet allowed");
 		}

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/Cell.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 public class Cell {
 	Cell(String r, String s, String t, String v, String text) {

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/CellStyle.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 
 import javax.xml.stream.XMLStreamException;

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/Fill.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 
 import javax.xml.stream.XMLStreamException;

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/Font.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 import javax.xml.stream.XMLStreamException;
 import javax.xml.stream.XMLStreamWriter;

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/FontRegion.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 public class FontRegion {
 

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/IndexedObject.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 public abstract class IndexedObject {
 	int index;

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/ParsableEntry.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 import javax.xml.stream.XMLStreamReader;
 

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/RichText.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 
 import java.util.ArrayList;

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/SerializableEntry.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 
 import javax.xml.stream.XMLStreamException;

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/SharedStringText.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 import javax.xml.stream.XMLStreamException;
 import javax.xml.stream.XMLStreamWriter;

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/Sheet.java

@@ -1,7 +1,6 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 
-import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -10,8 +9,8 @@ import javax.xml.stream.XMLStreamException;
 import javax.xml.stream.XMLStreamReader;
 import javax.xml.stream.XMLStreamWriter;
 
-import org.xbib.datastructures.xslx.SimpleXLSXWorkbook.ModifyEntry;
-import org.xbib.datastructures.xslx.SimpleXLSXWorkbook.XMLStreamCreator;
+import com.incesoft.tools.excel.xlsx.SimpleXLSXWorkbook.ModifyEntry;
+import com.incesoft.tools.excel.xlsx.SimpleXLSXWorkbook.XMLStreamCreator;
 
 /**
  * One Sheet in a workbook.It provides read and write functions of the
@@ -43,7 +42,7 @@ public class Sheet {
 	 */
 	boolean alreadyParsed = false;
 
-	void parseAllRows() throws IOException {
+	void parseAllRows() {
 		if (!alreadyParsed) {
 			alreadyParsed = true;
 			new SheetRowReader(this, workbook.getSheetReader(sheetIndex + 1),
@@ -217,7 +216,7 @@ public class Sheet {
 
 	}
 
-	public SheetRowReader newReader() throws IOException {
+	public SheetRowReader newReader() {
 		return new SheetRowReader(this,
 				workbook.getSheetReader(sheetIndex + 1), false);
 	}
@@ -241,7 +240,7 @@ public class Sheet {
 	private int rowCount = -2;
 
 	// count of the lazy or non-lazy rows
-	public int getRowCount() throws IOException, XMLStreamException {
+	public int getRowCount() {
 		if (alreadyParsed && addToMemory) {
 			return parsedRows.size();
 		}
@@ -251,10 +250,10 @@ public class Sheet {
 			try {
 				// <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 				// <worksheet ...><dimension ref="A1:C3"/>...<sheetData>
-				loopR:
-				while (reader.hasNext()) {
+				loopR: while (reader.hasNext()) {
 					int type = reader.next();
-                    if (type == XMLStreamReader.START_ELEMENT) {
+					switch (type) {
+					case XMLStreamReader.START_ELEMENT:
 						if ("dimension".equals(reader.getLocalName())) {
 							String v = reader.getAttributeValue(null, "ref");
 							if (v != null) {
@@ -276,10 +275,16 @@ public class Sheet {
 							if (r > rowCount)
 								rowCount = r;
 						}
+						break;
 					}
 				}
+			} catch (XMLStreamException e) {
+				throw new RuntimeException(e);
 			} finally {
+				try {
 					reader.close();
+				} catch (XMLStreamException e) {
+				}
 			}
 		}
 		return rowCount;
@@ -632,7 +637,16 @@ public class Sheet {
 
 	private boolean merged = false;
 
-	void mergeSheet() throws XMLStreamException, IOException {
+	/**
+	 * <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <worksheet
+	 * xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"
+	 * xmlns:r=
+	 * "http://schemas.openxmlformats.org/officeDocument/2006/relationships" ><sheetData>
+	 * 
+	 * @param writer
+	 * @throws XMLStreamException
+	 */
+	void mergeSheet() throws XMLStreamException {
 		if (merged) {
 			writeSheet();
 			return;

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/SheetCommentWriter.java

@@ -1,11 +1,11 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 import java.util.StringTokenizer;
 
 import javax.xml.stream.XMLStreamException;
 import javax.xml.stream.XMLStreamWriter;
 
-import org.xbib.datastructures.xslx.SimpleXLSXWorkbook.XMLStreamCreator;
+import com.incesoft.tools.excel.xlsx.SimpleXLSXWorkbook.XMLStreamCreator;
 
 public class SheetCommentWriter {
 

datastructures-xslx/src/main/java/com/incesoft/tools/excel/xlsx/SimpleXLSXWorkbook.java

@@ -1,4 +1,4 @@
-package org.xbib.datastructures.xslx;
+package com.incesoft.tools.excel.xlsx;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
@@ -32,12 +32,31 @@ import javax.xml.stream.XMLStreamWriter;
 /**
  * A simple implementation of OOXML(Excel part) to read and modify Excel 2007+
  * documents
+ *
  */
 public class SimpleXLSXWorkbook {
+	static {
+		// this the fastest stax implementation by test,especially when doing
+		// output
+		if ("false".equals(System.getProperty("ince.tools.excel.disableXMLOptimize"))) {
+			System.setProperty("javax.xml.stream.XMLInputFactory", "com.ctc.wstx.stax.WstxInputFactory");
+			System.setProperty("javax.xml.stream.XMLOutputFactory", "com.ctc.wstx.stax.WstxOutputFactory");
+		}
+	}
 
-	private static final XMLInputFactory inputFactory = XMLInputFactory.newInstance();
+	ZipFile zipfile;
 
-	private ZipFile zipfile;
+	private InputStream findData(String name) {
+		try {
+			ZipEntry entry = zipfile.getEntry(name);
+			if (entry != null) {
+				return zipfile.getInputStream(entry);
+			}
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+		return null;
+	}
 
 	private static final String PATH_XL_RELATION = "xl/_rels/workbook.xml.rels";
 
@@ -47,9 +66,9 @@ public class SimpleXLSXWorkbook {
 
 	private static final String PATH_CONTENT_TYPES = "[Content_Types].xml";
 
-	private static final List<Pattern> blackListPatterns = new ArrayList<Pattern>();
+	static private List<Pattern> blackListPatterns = new ArrayList<Pattern>();
 
-	private static final List<String> blackList = Arrays.asList(".*comments\\d+\\.xml", ".*calcChain\\.xml",
+	static private List<String> blackList = Arrays.asList(".*comments\\d+\\.xml", ".*calcChain\\.xml",
 			".*drawings/vmlDrawing\\d+\\.vml");
 	static {
 		for (String pstr : blackList) {
@@ -57,22 +76,16 @@ public class SimpleXLSXWorkbook {
 		}
 	}
 
-	public SimpleXLSXWorkbook() {
-		sheets.add(new Sheet(0, this));
-	}
-
-	public SimpleXLSXWorkbook(File file) throws IOException, XMLStreamException {
+	public SimpleXLSXWorkbook(File file) {
+		try {
 			this.zipfile = new ZipFile(file);
 			InputStream stream = findData(PATH_SHAREDSTRINGS);
 			if (stream != null) {
 				parseSharedStrings(stream);
 			}
-		for (int i = 0; true; i++) {
-			ZipEntry entry = zipfile.getEntry(getSheetPath(i + 1));
-			if (entry == null) {
-				break;
-			}
-			sheets.add(new Sheet(i, this));
+			initSheets();
+		} catch (Exception e) {
+			throw new RuntimeException(e);
 		}
 	}
 
@@ -157,6 +170,17 @@ public class SimpleXLSXWorkbook {
 		return null;
 	}
 
+	// int getSharedStringIndex(String string) {
+	// Integer i = (Integer) sharedStrings.inverseBidiMap().get(string);
+	// if (i != null) {
+	// return i;
+	// } else {
+	// return -1;
+	// }
+	// }
+
+	XMLInputFactory inputFactory = XMLInputFactory.newInstance();
+
 	private String getSheetPath(int i) {
 		return String.format(PATH_SHEET, i);
 	}
@@ -169,8 +193,7 @@ public class SimpleXLSXWorkbook {
 		return String.format(PATH_SHEET_COMMENT_VMLDRAWING, i);
 	}
 
-	private void parseSharedStrings(InputStream inputStream)
-			throws XMLStreamException {
+	private void parseSharedStrings(InputStream inputStream) throws Exception {
 		XMLStreamReader reader = inputFactory.createXMLStreamReader(inputStream);
 		int type;
 		boolean si = false;
@@ -218,23 +241,10 @@ public class SimpleXLSXWorkbook {
 	private static final String PATH_STYLES = "xl/styles.xml";
 
 	private static final String STR_XML_HEAD = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>";
-
 	private static final byte[] DATA_XL_WORKSHEETS__RELS_SHEET = (STR_XML_HEAD + "<Relationships xmlns=\"http://schemas.openxmlformats.org/package/2006/relationships\"></Relationships>")
 			.getBytes();
 
-
-	XMLStreamReader getSheetReader(Integer sheetId) throws IOException {
-		if (sheetId == null) {
-			sheetId = 1;
-		}
-		return getReader(getSheetPath(sheetId));
-	}
-
-	XMLStreamReader getStylesReader() throws IOException {
-		return getReader(PATH_STYLES);
-	}
-
-	private XMLStreamReader getReader(String resourceId) throws IOException {
+	XMLStreamReader getReader(String resourceId) {
 		InputStream stream = findData(resourceId);
 		if (stream == null) {
 			if (resourceId.startsWith("xl/worksheets/_rels/sheet")) {
@@ -252,9 +262,30 @@ public class SimpleXLSXWorkbook {
 		}
 	}
 
+	XMLStreamReader getSheetReader(Integer sheetId) {
+		if (sheetId == null) {
+			sheetId = 1;
+		}
+		return getReader(getSheetPath(sheetId));
+	}
+
+	XMLStreamReader getStylesReader() {
+		return getReader(PATH_STYLES);
+	}
+
 	// SHEET>>>
 	List<Sheet> sheets = new ArrayList<Sheet>();
 
+	private void initSheets() {
+		for (int i = 0; true; i++) {
+			ZipEntry entry = zipfile.getEntry(getSheetPath(i + 1));
+			if (entry == null) {
+				break;
+			}
+			sheets.add(new Sheet(i, this));
+		}
+	}
+
 	/**
 	 * create new sheet added to exists sheet list
 	 */
@@ -268,11 +299,11 @@ public class SimpleXLSXWorkbook {
 		return sheets.size();
 	}
 
-	public Sheet getSheet(int i) throws IOException {
+	public Sheet getSheet(int i) {
 		return getSheet(i, true);
 	}
 
-	public Sheet getSheet(int i, boolean parseAllRow) throws IOException {
+	public Sheet getSheet(int i, boolean parseAllRow) {
 		if (i >= sheets.size())
 			throw new IllegalArgumentException("sheet " + i + " not exists!SheetCount=" + sheets.size());
 		Sheet sheet = sheets.get(i);
@@ -388,7 +419,7 @@ public class SimpleXLSXWorkbook {
 		writer.writeEndElement();// end sst
 	}
 
-	private void mergeStyles(XMLStreamWriter writer) throws XMLStreamException, IOException {
+	private void mergeStyles(XMLStreamWriter writer) throws XMLStreamException {
 		prepareStylesCount();
 
 		XMLStreamReader reader = getStylesReader();
@@ -575,11 +606,12 @@ public class SimpleXLSXWorkbook {
 
 	boolean stylesCountLoaded = false;
 
-	private void prepareStylesCount() throws XMLStreamException, IOException {
+	private void prepareStylesCount() {
 		if (stylesCountLoaded)
 			return;
 		stylesCountLoaded = true;
 
+		try {
 			XMLStreamReader reader = getStylesReader();
 			loop1: while (reader.hasNext()) {
 				int event = reader.next();
@@ -602,6 +634,9 @@ public class SimpleXLSXWorkbook {
 					break;
 				}
 			}
+		} catch (XMLStreamException e) {
+			throw new RuntimeException(e);
+		}
 	}
 
 	/**
@@ -617,7 +652,7 @@ public class SimpleXLSXWorkbook {
 		return new Fill();
 	}
 
-	public CellStyle createStyle(Font font, Fill fill) throws XMLStreamException, IOException {
+	public CellStyle createStyle(Font font, Fill fill) {
 		if (font == null && fill == null) {
 			throw new IllegalArgumentException("either font or fill is required");
 		}
@@ -796,10 +831,14 @@ public class SimpleXLSXWorkbook {
 		/**
 		 * merge the sheet's modifications
 		 */
-		public void commitSheetModifications() throws XMLStreamException, IOException {
+		public void commitSheetModifications() {
+			try {
 				if (lastCommitSheet == null)
 					throw new IllegalStateException("plz call beginCommitSheet(Sheet) first");
 				lastCommitSheet.mergeSheet();
+			} catch (XMLStreamException e) {
+				throw new RuntimeException(e);
+			}
 		}
 
 		/**
@@ -1026,6 +1065,21 @@ public class SimpleXLSXWorkbook {
 		commiter.endCommit();
 	}
 
+	// MODIFY <<<
+
+	// TEST
+	public static void testMergeStyles(SimpleXLSXWorkbook excel, XMLStreamWriter writer) throws Exception {
+		// CellStyle style = excel.createStyle();
+		// style.setFont(new Font());
+		// style.getFont().setColor("FFFF0000");
+		// style = excel.createStyle();
+		// style.setFont(new Font());
+		// style.setFill(new Fill());
+		// style.getFont().setColor("FF0000FF");
+		// style.getFill().setFgColor("FF00FF00");
+
+	}
+
 	@SuppressWarnings("unchecked")
 	static private class BidirectionMap implements Map {
 		private Map values = new LinkedHashMap();
@@ -1087,12 +1141,4 @@ public class SimpleXLSXWorkbook {
 		}
 	}
 
-	private InputStream findData(String name) throws IOException {
-		ZipEntry entry = zipfile.getEntry(name);
-		if (entry != null) {
-			return zipfile.getInputStream(entry);
-		}
-		return null;
-	}
-
 }

datastructures-xslx/src/main/java/jxl/BooleanCell.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * This type represents the Microsoft concept of a Boolean.  Accordingly, this

datastructures-xslx/src/main/java/jxl/BooleanFormulaCell.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * A mixin interface for numerical formulas, which combines the interfaces

datastructures-xslx/src/main/java/jxl/Cell.java

@@ -17,9 +17,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
-import org.xbib.datastructures.xslx.jxl.format.CellFormat;
+import jxl.format.CellFormat;
 
 /**
  * Represents an individual Cell within a Sheet.  May be queried for its

datastructures-xslx/src/main/java/jxl/CellFeatures.java

@@ -17,9 +17,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
-import org.xbib.datastructures.xslx.jxl.biff.BaseCellFeatures;
+import jxl.biff.BaseCellFeatures;
 
 /**
  * Container for any additional cell features

datastructures-xslx/src/main/java/jxl/CellFormat.java

@@ -0,0 +1,28 @@
+/*********************************************************************
+ *
+ *      Copyright (C) 2002 Andrew Khan
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ ***************************************************************************/
+
+package jxl;
+
+/**
+ * Interface for cell formats - used for typing information
+ *
+ * @deprecated Repackaged as jxl.format.CellFormat
+ */
+public interface CellFormat extends jxl.format.CellFormat {
+}

datastructures-xslx/src/main/java/jxl/CellReferenceHelper.java

@@ -17,10 +17,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
-import org.xbib.datastructures.xslx.jxl.write.WritableWorkbook;
-import org.xbib.datastructures.xslx.jxl.biff.formula.ExternalSheet;
+import jxl.write.WritableWorkbook;
 
 /**
  * Exposes some cell reference helper methods to the public interface.
@@ -42,7 +41,7 @@ public final class CellReferenceHelper {
      * @param buf    the string buffer to append
      */
     public static void getCellReference(int column, int row, StringBuffer buf) {
-        org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getCellReference(column, row, buf);
+        jxl.biff.CellReferenceHelper.getCellReference(column, row, buf);
     }
 
     /**
@@ -59,7 +58,7 @@ public final class CellReferenceHelper {
                                         int row,
                                         boolean rowabs,
                                         StringBuffer buf) {
-        org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getCellReference(column, colabs,
+        jxl.biff.CellReferenceHelper.getCellReference(column, colabs,
                 row, rowabs,
                 buf);
     }
@@ -73,7 +72,7 @@ public final class CellReferenceHelper {
      * @return the cell reference
      */
     public static String getCellReference(int column, int row) {
-        return org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getCellReference(column, row);
+        return jxl.biff.CellReferenceHelper.getCellReference(column, row);
     }
 
     /**
@@ -83,7 +82,7 @@ public final class CellReferenceHelper {
      * @return the column portion of the cell reference
      */
     public static int getColumn(String s) {
-        return org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getColumn(s);
+        return jxl.biff.CellReferenceHelper.getColumn(s);
     }
 
     /**
@@ -93,7 +92,7 @@ public final class CellReferenceHelper {
      * @return the letter for that column number
      */
     public static String getColumnReference(int c) {
-        return org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getColumnReference(c);
+        return jxl.biff.CellReferenceHelper.getColumnReference(c);
     }
 
     /**
@@ -103,7 +102,7 @@ public final class CellReferenceHelper {
      * @return the row number
      */
     public static int getRow(String s) {
-        return org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getRow(s);
+        return jxl.biff.CellReferenceHelper.getRow(s);
     }
 
     /**
@@ -113,7 +112,7 @@ public final class CellReferenceHelper {
      * @return TRUE if the column is relative, FALSE otherwise
      */
     public static boolean isColumnRelative(String s) {
-        return org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.isColumnRelative(s);
+        return jxl.biff.CellReferenceHelper.isColumnRelative(s);
     }
 
     /**
@@ -123,7 +122,7 @@ public final class CellReferenceHelper {
      * @return TRUE if the row is relative, FALSE otherwise
      */
     public static boolean isRowRelative(String s) {
-        return org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.isRowRelative(s);
+        return jxl.biff.CellReferenceHelper.isRowRelative(s);
     }
 
     /**
@@ -139,8 +138,8 @@ public final class CellReferenceHelper {
     public static void getCellReference
     (int sheet, int column, int row,
      Workbook workbook, StringBuffer buf) {
-        org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getCellReference
-                (sheet, column, row, (ExternalSheet) workbook, buf);
+        jxl.biff.CellReferenceHelper.getCellReference
+                (sheet, column, row, (jxl.biff.formula.ExternalSheet) workbook, buf);
     }
 
     /**
@@ -158,8 +157,8 @@ public final class CellReferenceHelper {
                                         int row,
                                         WritableWorkbook workbook,
                                         StringBuffer buf) {
-        org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getCellReference
-                (sheet, column, row, (ExternalSheet) workbook, buf);
+        jxl.biff.CellReferenceHelper.getCellReference
+                (sheet, column, row, (jxl.biff.formula.ExternalSheet) workbook, buf);
     }
 
     /**
@@ -181,9 +180,9 @@ public final class CellReferenceHelper {
                                         boolean rowabs,
                                         Workbook workbook,
                                         StringBuffer buf) {
-        org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getCellReference
+        jxl.biff.CellReferenceHelper.getCellReference
                 (sheet, column, colabs, row, rowabs,
-                        (ExternalSheet) workbook, buf);
+                        (jxl.biff.formula.ExternalSheet) workbook, buf);
     }
 
     /**
@@ -200,8 +199,8 @@ public final class CellReferenceHelper {
                                           int column,
                                           int row,
                                           Workbook workbook) {
-        return org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getCellReference
-                (sheet, column, row, (ExternalSheet) workbook);
+        return jxl.biff.CellReferenceHelper.getCellReference
+                (sheet, column, row, (jxl.biff.formula.ExternalSheet) workbook);
     }
 
     /**
@@ -218,8 +217,8 @@ public final class CellReferenceHelper {
                                           int column,
                                           int row,
                                           WritableWorkbook workbook) {
-        return org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getCellReference
-                (sheet, column, row, (ExternalSheet) workbook);
+        return jxl.biff.CellReferenceHelper.getCellReference
+                (sheet, column, row, (jxl.biff.formula.ExternalSheet) workbook);
     }
 
 
@@ -230,7 +229,7 @@ public final class CellReferenceHelper {
      * @return the sheet name
      */
     public static String getSheet(String ref) {
-        return org.xbib.datastructures.xslx.jxl.biff.CellReferenceHelper.getSheet(ref);
+        return jxl.biff.CellReferenceHelper.getSheet(ref);
     }
 
     /**

datastructures-xslx/src/main/java/jxl/CellType.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * An enumeration type listing the available content types for a cell

datastructures-xslx/src/main/java/jxl/CellView.java

@@ -17,9 +17,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
-import org.xbib.datastructures.xslx.jxl.format.CellFormat;
+import jxl.format.CellFormat;
 
 /**
  * This is a bean which client applications may use to get/set various

datastructures-xslx/src/main/java/jxl/DateCell.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 import java.text.DateFormat;
 import java.util.Date;

datastructures-xslx/src/main/java/jxl/DateFormulaCell.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * A mixin interface for date formulas, which combines the interfaces

datastructures-xslx/src/main/java/jxl/ErrorCell.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * This type represents a cell which contains an error.  This error will

datastructures-xslx/src/main/java/jxl/ErrorFormulaCell.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * A mixin interface for numerical formulas, which combines the interfaces

datastructures-xslx/src/main/java/jxl/FormulaCell.java

@@ -17,9 +17,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
-import org.xbib.datastructures.xslx.jxl.biff.formula.FormulaException;
+import jxl.biff.formula.FormulaException;
 
 /**
  * Interface for formulas which allow clients to read the Excel formula

datastructures-xslx/src/main/java/jxl/HeaderFooter.java

@@ -17,12 +17,12 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * Class which represents an Excel header or footer.
  */
-public final class HeaderFooter extends org.xbib.datastructures.xslx.jxl.biff.HeaderFooter {
+public final class HeaderFooter extends jxl.biff.HeaderFooter {
     /**
      * Default constructor.
      */
@@ -98,7 +98,7 @@ public final class HeaderFooter extends org.xbib.datastructures.xslx.jxl.biff.He
      *
      * @return the created contents
      */
-    protected org.xbib.datastructures.xslx.jxl.biff.HeaderFooter.Contents createContents() {
+    protected jxl.biff.HeaderFooter.Contents createContents() {
         return new Contents();
     }
 
@@ -108,7 +108,7 @@ public final class HeaderFooter extends org.xbib.datastructures.xslx.jxl.biff.He
      * @param s the string to create the contents
      * @return the created contents
      */
-    protected org.xbib.datastructures.xslx.jxl.biff.HeaderFooter.Contents createContents(String s) {
+    protected jxl.biff.HeaderFooter.Contents createContents(String s) {
         return new Contents(s);
     }
 
@@ -118,15 +118,15 @@ public final class HeaderFooter extends org.xbib.datastructures.xslx.jxl.biff.He
      * @param c the contents to copy
      * @return the new contents
      */
-    protected org.xbib.datastructures.xslx.jxl.biff.HeaderFooter.Contents
-    createContents(org.xbib.datastructures.xslx.jxl.biff.HeaderFooter.Contents c) {
+    protected jxl.biff.HeaderFooter.Contents
+    createContents(jxl.biff.HeaderFooter.Contents c) {
         return new Contents((Contents) c);
     }
 
     /**
      * The contents - a simple wrapper around a string buffer
      */
-    public static class Contents extends org.xbib.datastructures.xslx.jxl.biff.HeaderFooter.Contents {
+    public static class Contents extends jxl.biff.HeaderFooter.Contents {
         /**
          * The constructor
          */

datastructures-xslx/src/main/java/jxl/Hyperlink.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 import java.io.File;
 import java.net.URL;

datastructures-xslx/src/main/java/jxl/Image.java

@@ -17,10 +17,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 import java.io.File;
-import org.xbib.datastructures.xslx.jxl.common.LengthUnit;
+import jxl.common.LengthUnit;
 
 /**
  * Accessor functions for an image

datastructures-xslx/src/main/java/jxl/JXLException.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * Base exception class for JExcelAPI  exceptions

datastructures-xslx/src/main/java/jxl/LabelCell.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * A label cell

datastructures-xslx/src/main/java/jxl/NumberCell.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 import java.text.NumberFormat;
 

datastructures-xslx/src/main/java/jxl/NumberFormulaCell.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * A mixin interface for numerical formulas, which combines the interfaces

datastructures-xslx/src/main/java/jxl/Range.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * Represents a 3-D range of cells in a workbook.  This object is

datastructures-xslx/src/main/java/jxl/Sheet.java

@@ -17,10 +17,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 import java.util.regex.Pattern;
-import org.xbib.datastructures.xslx.jxl.format.CellFormat;
+import jxl.format.CellFormat;
 
 /**
  * Represents a sheet within a workbook.  Provides a handle to the individual

datastructures-xslx/src/main/java/jxl/SheetSettings.java

@@ -17,13 +17,13 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
-import org.xbib.datastructures.xslx.jxl.biff.SheetRangeImpl;
-import org.xbib.datastructures.xslx.jxl.common.Assert;
-import org.xbib.datastructures.xslx.jxl.format.PageOrder;
-import org.xbib.datastructures.xslx.jxl.format.PageOrientation;
-import org.xbib.datastructures.xslx.jxl.format.PaperSize;
+import jxl.biff.SheetRangeImpl;
+import jxl.common.Assert;
+import jxl.format.PageOrder;
+import jxl.format.PageOrientation;
+import jxl.format.PaperSize;
 
 /**
  * This is a bean which client applications may use to get/set various

datastructures-xslx/src/main/java/jxl/StringFormulaCell.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 /**
  * A mixin interface for numerical formulas, which combines the interfaces

datastructures-xslx/src/main/java/jxl/Workbook.java

@@ -17,19 +17,19 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import org.xbib.datastructures.xslx.jxl.read.biff.BiffException;
-import org.xbib.datastructures.xslx.jxl.read.biff.File;
-import org.xbib.datastructures.xslx.jxl.read.biff.PasswordException;
-import org.xbib.datastructures.xslx.jxl.read.biff.WorkbookParser;
-import org.xbib.datastructures.xslx.jxl.write.WritableWorkbook;
-import org.xbib.datastructures.xslx.jxl.write.biff.WritableWorkbookImpl;
+import jxl.read.biff.BiffException;
+import jxl.read.biff.File;
+import jxl.read.biff.PasswordException;
+import jxl.read.biff.WorkbookParser;
+import jxl.write.WritableWorkbook;
+import jxl.write.biff.WritableWorkbookImpl;
 
 /**
  * Represents a Workbook.  Contains the various factory methods and provides

datastructures-xslx/src/main/java/jxl/WorkbookSettings.java

@@ -17,14 +17,14 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl;
+package jxl;
 
 import java.io.File;
 import java.util.HashMap;
 import java.util.Locale;
-import org.xbib.datastructures.xslx.jxl.biff.CountryCode;
-import org.xbib.datastructures.xslx.jxl.biff.formula.FunctionNames;
-import org.xbib.datastructures.xslx.jxl.common.Logger;
+import jxl.biff.CountryCode;
+import jxl.biff.formula.FunctionNames;
+import jxl.common.Logger;
 
 /**
  * This is a bean which client applications may use to set various advanced

datastructures-xslx/src/main/java/jxl/biff/AutoFilter.java

@@ -17,10 +17,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
 import java.io.IOException;
-import org.xbib.datastructures.xslx.jxl.write.biff.File;
+import jxl.write.biff.File;
 
 /**
  * Information for autofiltering

datastructures-xslx/src/main/java/jxl/biff/AutoFilterInfoRecord.java

@@ -17,10 +17,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
-import org.xbib.datastructures.xslx.jxl.common.Logger;
-import org.xbib.datastructures.xslx.jxl.read.biff.Record;
+import jxl.common.Logger;
+import jxl.read.biff.Record;
 
 /**
  * Range information for conditional formatting

datastructures-xslx/src/main/java/jxl/biff/AutoFilterRecord.java

@@ -17,10 +17,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
-import org.xbib.datastructures.xslx.jxl.common.Logger;
-import org.xbib.datastructures.xslx.jxl.read.biff.Record;
+import jxl.common.Logger;
+import jxl.read.biff.Record;
 
 /**
  * Range information for conditional formatting

datastructures-xslx/src/main/java/jxl/biff/BaseCellFeatures.java

@@ -17,16 +17,16 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
 import java.util.Collection;
-import org.xbib.datastructures.xslx.jxl.CellReferenceHelper;
-import org.xbib.datastructures.xslx.jxl.Range;
-import org.xbib.datastructures.xslx.jxl.biff.drawing.ComboBox;
-import org.xbib.datastructures.xslx.jxl.biff.drawing.Comment;
-import org.xbib.datastructures.xslx.jxl.common.Assert;
-import org.xbib.datastructures.xslx.jxl.common.Logger;
-import org.xbib.datastructures.xslx.jxl.write.biff.CellValue;
+import jxl.CellReferenceHelper;
+import jxl.Range;
+import jxl.biff.drawing.ComboBox;
+import jxl.biff.drawing.Comment;
+import jxl.common.Assert;
+import jxl.common.Logger;
+import jxl.write.biff.CellValue;
 
 /**
  * Container for any additional cell features

datastructures-xslx/src/main/java/jxl/biff/BaseCompoundFile.java

@@ -17,10 +17,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
-import org.xbib.datastructures.xslx.jxl.common.Assert;
-import org.xbib.datastructures.xslx.jxl.common.Logger;
+import jxl.common.Assert;
+import jxl.common.Logger;
 
 /**
  * Contains the common data for a compound file

datastructures-xslx/src/main/java/jxl/biff/BuiltInFormat.java

@@ -17,9 +17,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
-import org.xbib.datastructures.xslx.jxl.format.Format;
+import jxl.format.Format;
 
 /**
  * The excel string for the various built in formats.  Used to present

datastructures-xslx/src/main/java/jxl/biff/BuiltInName.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
 /**
  * Enumeration of built in names

datastructures-xslx/src/main/java/jxl/biff/BuiltInStyle.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
 /**
  * Represents a built in, rather than a user defined, style.

datastructures-xslx/src/main/java/jxl/biff/ByteArray.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
 /**
  * A growable array of bytes

datastructures-xslx/src/main/java/jxl/biff/ByteData.java

@@ -17,7 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
 /**
  * Interface which provides a method for transferring chunks of binary

datastructures-xslx/src/main/java/jxl/biff/CellFinder.java

@@ -17,14 +17,14 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import org.xbib.datastructures.xslx.jxl.Cell;
-import org.xbib.datastructures.xslx.jxl.CellType;
-import org.xbib.datastructures.xslx.jxl.LabelCell;
-import org.xbib.datastructures.xslx.jxl.Sheet;
+import jxl.Cell;
+import jxl.CellType;
+import jxl.LabelCell;
+import jxl.Sheet;
 
 /**
  * Refactorisation to provide more sophisticated find cell by contents

datastructures-xslx/src/main/java/jxl/biff/CellReferenceHelper.java

@@ -17,10 +17,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
-import org.xbib.datastructures.xslx.jxl.biff.formula.ExternalSheet;
-import org.xbib.datastructures.xslx.jxl.common.Logger;
+import jxl.biff.formula.ExternalSheet;
+import jxl.common.Logger;
 
 /**
  * A helper to transform between excel cell references and

datastructures-xslx/src/main/java/jxl/biff/ConditionalFormat.java

@@ -17,12 +17,12 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Iterator;
-import org.xbib.datastructures.xslx.jxl.write.biff.File;
+import jxl.write.biff.File;
 
 /**
  * Class containing the CONDFMT and CF records for conditionally formatting

datastructures-xslx/src/main/java/jxl/biff/ConditionalFormatRangeRecord.java

@@ -17,10 +17,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
-import org.xbib.datastructures.xslx.jxl.common.Logger;
-import org.xbib.datastructures.xslx.jxl.read.biff.Record;
+import jxl.common.Logger;
+import jxl.read.biff.Record;
 
 /**
  * Range information for conditional formatting

datastructures-xslx/src/main/java/jxl/biff/ConditionalFormatRecord.java

@@ -17,10 +17,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
-import org.xbib.datastructures.xslx.jxl.common.Logger;
-import org.xbib.datastructures.xslx.jxl.read.biff.Record;
+import jxl.common.Logger;
+import jxl.read.biff.Record;
 
 /**
  * The conditional format conditions

datastructures-xslx/src/main/java/jxl/biff/ContinueRecord.java

@@ -17,9 +17,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
-import org.xbib.datastructures.xslx.jxl.read.biff.Record;
+import jxl.read.biff.Record;
 
 /**
  * A continue record -  only used explicitly in special circumstances, as

datastructures-xslx/src/main/java/jxl/biff/CountryCode.java

@@ -17,9 +17,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
-import org.xbib.datastructures.xslx.jxl.common.Logger;
+import jxl.common.Logger;
 
 /**
  * Enumeration type for the excel country codes

datastructures-xslx/src/main/java/jxl/biff/DVParser.java

@@ -17,19 +17,19 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
 import java.text.DecimalFormat;
 import java.text.MessageFormat;
 import java.util.Collection;
 import java.util.Iterator;
-import org.xbib.datastructures.xslx.jxl.WorkbookSettings;
-import org.xbib.datastructures.xslx.jxl.biff.formula.ExternalSheet;
-import org.xbib.datastructures.xslx.jxl.biff.formula.FormulaException;
-import org.xbib.datastructures.xslx.jxl.biff.formula.FormulaParser;
-import org.xbib.datastructures.xslx.jxl.biff.formula.ParseContext;
-import org.xbib.datastructures.xslx.jxl.common.Assert;
-import org.xbib.datastructures.xslx.jxl.common.Logger;
+import jxl.WorkbookSettings;
+import jxl.biff.formula.ExternalSheet;
+import jxl.biff.formula.FormulaException;
+import jxl.biff.formula.FormulaParser;
+import jxl.biff.formula.ParseContext;
+import jxl.common.Assert;
+import jxl.common.Logger;
 
 /**
  * Class which parses the binary data associated with Data Validity (DV)

datastructures-xslx/src/main/java/jxl/biff/DValParser.java

@@ -17,9 +17,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  ***************************************************************************/
 
-package org.xbib.datastructures.xslx.jxl.biff;
+package jxl.biff;
 
-import org.xbib.datastructures.xslx.jxl.common.Logger;
+import jxl.common.Logger;
 
 /**
  * Class which parses the binary data associated with Data Validity (DVal)