add settings refresher

content-core/src/main/java/org/xbib/content/settings/Settings.java

@@ -15,6 +15,8 @@ import java.io.StringWriter;
 import java.io.Writer;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.time.DateTimeException;
 import java.time.LocalDate;
 import java.time.format.DateTimeFormatter;
@@ -24,23 +26,39 @@ import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
 /**
  *
  */
-public class Settings {
+public class Settings implements AutoCloseable {
 
     private static final Logger logger = Logger.getLogger(Settings.class.getName());
 
     public static final Settings EMPTY_SETTINGS = new Builder().build();
-    public static final String[] EMPTY_ARRAY = new String[0];
-    public static final int BUFFER_SIZE = 1024 * 8;
-    private final Map<String, String> map;
 
-    private Settings(Map<String, String> settings) {
+    public static final String[] EMPTY_ARRAY = new String[0];
-        this.map = new HashMap<>(settings);
+
+    public static final int BUFFER_SIZE = 1024 * 8;
+
+    private DefaultSettingsRefresher refresher;
+
+    private Map<String, String> map;
+
+    private Settings(Map<String, String> map) {
+        this(map, null, 0L, 0L, TimeUnit.SECONDS);
+    }
+
+    private Settings(Map<String, String> map, Path path, long initialDelay, long period, TimeUnit timeUnit) {
+        this.map = new LinkedHashMap<>(map);
+        if (path != null && initialDelay >= 0L && period > 0L) {
+            this.refresher = new DefaultSettingsRefresher(path, initialDelay, period, timeUnit);
+        }
     }
 
     public static Settings readSettingsFromMap(Map<String, Object> map) throws IOException {
@@ -175,11 +193,7 @@ public class Settings {
     }
 
     public String get(String setting) {
-        String retVal = map.get(setting);
+        return map.get(setting);
-        if (retVal != null) {
-            return retVal;
-        }
-        return null;
     }
 
     public String get(String setting, String defaultValue) {
@@ -298,11 +312,7 @@ public class Settings {
                 }
                 String name = nameValue.substring(0, dotIndex);
                 String value = nameValue.substring(dotIndex + 1);
-                Map<String, String> groupSettings = hashMap.get(name);
+                Map<String, String> groupSettings = hashMap.computeIfAbsent(name, k -> new LinkedHashMap<>());
-                if (groupSettings == null) {
-                    groupSettings = new LinkedHashMap<>();
-                    hashMap.put(name, groupSettings);
-                }
                 groupSettings.put(value, get(setting));
             }
         }
@@ -394,6 +404,13 @@ public class Settings {
         return map;
     }
 
+    @Override
+    public void close() throws IOException {
+        if (refresher != null) {
+            refresher.stop();
+        }
+    }
+
     /**
      *
      */
@@ -401,6 +418,14 @@ public class Settings {
 
         private final Map<String, String> map = new LinkedHashMap<>();
 
+        private Path path;
+
+        private long initialDelay;
+
+        private long period;
+
+        private TimeUnit timeUnit;
+
         private Builder() {
         }
 
@@ -709,14 +734,54 @@ public class Settings {
 
         public Builder replacePropertyPlaceholders(PropertyPlaceholder propertyPlaceholder,
                                                    PlaceholderResolver placeholderResolver) {
-            for (Map.Entry<String, String> entry : map.entrySet()) {
+            map.replaceAll((k, v) -> propertyPlaceholder.replacePlaceholders(v, placeholderResolver));
-                map.put(entry.getKey(), propertyPlaceholder.replacePlaceholders(entry.getValue(), placeholderResolver));
+            return this;
         }
+
+        public Builder setRefresh(Path path, long initialDelay, long period, TimeUnit timeUnit) {
+            this.path = path;
+            this.initialDelay = initialDelay;
+            this.period = period;
+            this.timeUnit = timeUnit;
             return this;
         }
 
         public Settings build() {
-            return new Settings(map);
+            return new Settings(map, path, initialDelay, period, timeUnit);
+        }
+    }
+
+    class DefaultSettingsRefresher implements Runnable {
+
+        private final Path path;
+
+        private final ScheduledExecutorService executorService;
+
+        private final AtomicBoolean closed;
+
+        DefaultSettingsRefresher(Path path, long initialDelay, long period, TimeUnit timeUnit) {
+            this.path = path;
+            this.executorService = Executors.newSingleThreadScheduledExecutor();
+            executorService.scheduleAtFixedRate(this, initialDelay, period, timeUnit);
+            this.closed = new AtomicBoolean();
+        }
+
+        @Override
+        public void run() {
+            try {
+                if (!closed.get()) {
+                    String settingsSource = Files.readString(path);
+                    SettingsLoader settingsLoader = SettingsLoaderService.loaderFromResource(path.toString());
+                    map = settingsLoader.load(settingsSource);
+                }
+            } catch (IOException e) {
+                throw new RuntimeException("unable to refresh settings from path " + path, e);
+            }
+        }
+
+        public void stop() {
+            closed.set(true);
+            executorService.shutdownNow();
         }
     }
 }

content-core/src/test/java/org/xbib/content/settings/SettingsTest.java

@@ -12,12 +12,14 @@ import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.StringReader;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.TimeUnit;
 import java.util.logging.Logger;
 
 /**
@@ -114,7 +116,7 @@ public class SettingsTest extends Assert {
         Settings settings = Settings.settingsBuilder()
                 .loadFromSystemEnvironment()
                 .build();
-        assertTrue(!settings.getAsMap().isEmpty());
+        assertFalse(settings.getAsMap().isEmpty());
     }
 
     @Test
@@ -122,7 +124,7 @@ public class SettingsTest extends Assert {
         Settings settings = Settings.settingsBuilder()
                 .loadFromSystemProperties()
                 .build();
-        assertTrue(!settings.getAsMap().isEmpty());
+        assertFalse(settings.getAsMap().isEmpty());
     }
 
     @Test
@@ -176,4 +178,14 @@ public class SettingsTest extends Assert {
         Map<String, String> result = loader.load(map);
         assertEquals("{code.a=b, code.b=c, name.a=b, name.b=c, list.0=a, list.1=b, null=null}", result.toString());
     }
+
+    @Test
+    public void testRefresher() throws Exception {
+        Settings settings = Settings.settingsBuilder()
+                .setRefresh(Paths.get("src/test/resources/settings.json"), 0L, 1L, TimeUnit.DAYS)
+                .build();
+        Thread.sleep(1000L);
+        assertEquals("Jörg Prante", settings.get("name"));
+        settings.close();
+    }
 }

content-core/src/test/resources/settings.json

@@ -0,0 +1,3 @@
+{
+  "name": "Jörg Prante"
+}

gradle.properties

@@ -1,6 +1,6 @@
 group = org.xbib
 name = content
-version = 2.0.5
+version = 2.0.6
 
 xbib-net.version = 2.0.3
 jackson.version = 2.9.10

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,5 @@
-#Mon Jan 13 14:36:01 CET 2020
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.2-all.zip
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.2-bin.zip
 zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists