add self property placeholder resolving

gradle.properties

@@ -1,3 +1,3 @@
 group = org.xbib
 name = datastructures
-version = 5.2.4
+version = 5.3.0

settings-api/src/main/java/org/xbib/settings/PropertyPlaceholder.java

@@ -53,7 +53,7 @@ public class PropertyPlaceholder {
             if (endIndex != -1) {
                 String placeholder = sb.substring(startIndex + this.placeholderPrefix.length(), endIndex);
                 if (!visitedPlaceholders.add(placeholder)) {
-                    throw new IllegalArgumentException("Circular placeholder reference '" + placeholder + "' in property definitions");
+                    throw new IllegalArgumentException("Circular placeholder reference '" + placeholder + "' in definitions");
                 }
                 placeholder = parseStringValue(placeholder, placeholderResolver, visitedPlaceholders);
                 int defaultValueIdx = placeholder.indexOf(':');
@@ -71,7 +71,6 @@ public class PropertyPlaceholder {
                     sb.replace(startIndex, endIndex + this.placeholderSuffix.length(), propVal);
                     startIndex = sb.indexOf(this.placeholderPrefix, startIndex + propVal.length());
                 } else if (this.ignoreUnresolvablePlaceholders) {
-                    // Proceed with unprocessed value.
                     startIndex = sb.indexOf(this.placeholderPrefix, endIndex + this.placeholderSuffix.length());
                 } else {
                     throw new IllegalArgumentException("could not resolve placeholder '" + placeholder + "'");

settings-datastructures/src/main/java/org/xbib/settings/datastructures/DatastructureSettingsBuilder.java

@@ -15,7 +15,7 @@ import java.io.InputStreamReader;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
 import java.time.DateTimeException;
-import java.time.LocalDate;
+import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.List;
 import java.util.Map;
@@ -23,9 +23,6 @@ import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
-/**
- *
- */
 public class DatastructureSettingsBuilder implements SettingsBuilder {
 
     private final SettingsLoaderService settingsLoaderService;
@@ -37,10 +34,6 @@ public class DatastructureSettingsBuilder implements SettingsBuilder {
         this.map = TinyMap.builder();
     }
 
-    public String remove(String key) {
-        return map.remove(key);
-    }
-
     @Override
     public boolean isEmpty() {
         return map.isEmpty();
@@ -190,7 +183,7 @@ public class DatastructureSettingsBuilder implements SettingsBuilder {
             if (values[i] == null) {
                 continue;
             }
-            put(settingPrefix + "" + groupName + "." + settings[i], values[i]);
+            put(settingPrefix + groupName + "." + settings[i], values[i]);
         }
         return this;
     }
@@ -258,7 +251,7 @@ public class DatastructureSettingsBuilder implements SettingsBuilder {
     }
 
     /**
-     * Load system properties to this settings.
+     * Load all system properties to this settings.
      *
      * @return builder
      */
@@ -271,7 +264,7 @@ public class DatastructureSettingsBuilder implements SettingsBuilder {
     }
 
     /**
-     * Load system environment to this settings.
+     * Load all system environment to this settings.
      *
      * @return builder
      */
@@ -294,22 +287,30 @@ public class DatastructureSettingsBuilder implements SettingsBuilder {
     public DatastructureSettingsBuilder replacePropertyPlaceholders() {
         return replacePropertyPlaceholders(new PropertyPlaceholder("${", "}", false),
                 placeholderName -> {
-                    // system property
+                    // lookup system property, even is not loaded
                     String value = System.getProperty(placeholderName);
                     if (value != null) {
                         return value;
                     }
-                    // environment
+                    // lookup environment, even it is not loaded
                     value = System.getenv(placeholderName);
                     if (value != null) {
                         return value;
                     }
-                    // current date
-                    try {
-                        return DateTimeFormatter.ofPattern(placeholderName).format(LocalDate.now());
-                    } catch (IllegalArgumentException | DateTimeException e) {
-                        return map.get(placeholderName);
+                    // lookup self
+                    value = map.get(placeholderName);
+                    if (value != null) {
+                        return value;
                     }
+                    // special case: pattern for current timestamp
+                    if (placeholderName.startsWith("ts_")) {
+                        try {
+                            return DateTimeFormatter.ofPattern(placeholderName.substring(3)).format(LocalDateTime.now());
+                        } catch (IllegalArgumentException | DateTimeException e) {
+                            return LocalDateTime.now().toString();
+                        }
+                    }
+                    throw new IllegalArgumentException("unable to resolve " + placeholderName);
                 }
         );
     }
@@ -329,4 +330,8 @@ public class DatastructureSettingsBuilder implements SettingsBuilder {
     public DatastructureSettings build() {
         return new DatastructureSettings(map.build());
     }
+
+    public void remove(String key) {
+        map.remove(key);
+    }
 }

settings-datastructures/src/test/java/org/xbib/settings/datastructures/test/SettingsTest.java

@@ -84,8 +84,9 @@ public class SettingsTest {
 
     @Test
     public void testCurrentYearInSettings() {
+        // prefix "ts_" is reserved for date/time patterns and will resolve into current timestamp
         Settings settings = Settings.settingsBuilder()
-                .put("date", "${yyyy}")
+                .put("date", "${ts_yyyy}")
                 .replacePropertyPlaceholders()
                 .build();
         assertEquals(LocalDate.now().getYear(), Integer.parseInt(settings.get("date")));
@@ -131,4 +132,14 @@ public class SettingsTest {
                 .build();
         assertEquals("{a.b=c}", settings.getAsMap().toString());
     }
+
+    @Test
+    public void testSelfPropertyPlaceHolder() {
+        Settings settings = Settings.settingsBuilder()
+                .put("host", "localhost")
+                .put("anotherhost", "${host}")
+                .replacePropertyPlaceholders()
+                .build();
+        assertEquals("localhost", settings.get("anotherhost"));
+    }
 }