Completed the detection and processing of configuration file changes.

rapidoid-commons/src/main/java/org/rapidoid/collection/Coll.java

@@ -3,7 +3,9 @@
 import org.rapidoid.RapidoidThing;
 import org.rapidoid.annotation.Authors;
 import org.rapidoid.annotation.Since;
+import org.rapidoid.cls.Cls;
 import org.rapidoid.commons.Err;
+import org.rapidoid.data.JSON;
 import org.rapidoid.datamodel.DataItems;
 import org.rapidoid.lambda.Mapper;
 import org.rapidoid.u.U;
@@ -356,4 +358,31 @@ public static <K, V> ChangeTrackingMap<K, V> trackChanges(Map<K, V> map, AtomicB
 		return new ChangeTrackingMap<K, V>(map, dirtyFlag);
 	}
 
+	public static <T> Map<String, T> toBeanMap(Map<String, Object> data, Class<T> type) {
+		Map<String, T> map = U.map();
+
+		for (Map.Entry<String, Object> e : data.entrySet()) {
+			T bean;
+			Object value = e.getValue();
+
+			if (value instanceof Map) {
+				bean = JSON.MAPPER.convertValue(value, type);
+
+			} else if (value instanceof String) {
+				bean = Cls.newInstance(type, value);
+
+			} else {
+				throw U.rte("Unsupported configuration type: %s", Cls.of(value));
+			}
+
+			map.put(e.getKey(), bean);
+		}
+
+		return Collections.unmodifiableMap(map);
+	}
+
+	public static Map<String, Object> deepCopyOf(Map<String, Object> map) {
+		return JSON.parseMap(JSON.stringify(map)); // FIXME proper implementation
+	}
+
 }

rapidoid-commons/src/main/java/org/rapidoid/config/Config.java

@@ -22,6 +22,7 @@
 
 import org.rapidoid.annotation.Authors;
 import org.rapidoid.annotation.Since;
+import org.rapidoid.lambda.Operation;
 
 import java.util.List;
 import java.util.Map;
@@ -95,4 +96,10 @@ public interface Config extends BasicConfig {
 
 	boolean isInitialized();
 
+	ConfigChanges getChangesSince(Config previousConfig);
+
+	void addChangeListener(Operation<ConfigChanges> configChangeListener);
+
+	void removeChangeListener(Operation<ConfigChanges> configChangeListener);
+
 }

rapidoid-commons/src/main/java/org/rapidoid/config/ConfigBase.java

@@ -27,6 +27,7 @@
 import org.rapidoid.u.U;
 
 import java.util.Map;
+import java.util.Set;
 
 @Authors("Nikolche Mihajlovski")
 @Since("5.2.0")
@@ -40,6 +41,8 @@ public class ConfigBase extends RapidoidInitializer {
 
 	final Map<String, Object> initial = Coll.synchronizedMap();
 
+	final Set<ConfigChangeListener> configChangesListeners = Coll.synchronizedSet();
+
 	volatile boolean initializing;
 
 	volatile boolean initialized;

rapidoid-commons/src/main/java/org/rapidoid/config/ConfigChangeListener.java

@@ -0,0 +1,59 @@
+package org.rapidoid.config;
+
+import org.rapidoid.RapidoidThing;
+import org.rapidoid.annotation.Authors;
+import org.rapidoid.annotation.Since;
+import org.rapidoid.lambda.Operation;
+
+import java.util.List;
+
+/*
+ * #%L
+ * rapidoid-commons
+ * %%
+ * Copyright (C) 2014 - 2016 Nikolche Mihajlovski and contributors
+ * %%
+ * 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.
+ * #L%
+ */
+
+@Authors("Nikolche Mihajlovski")
+@Since("5.3.0")
+class ConfigChangeListener extends RapidoidThing {
+
+	final List<String> keys;
+	final Operation<ConfigChanges> operation;
+
+	ConfigChangeListener(List<String> keys, Operation<ConfigChanges> operation) {
+		this.keys = keys;
+		this.operation = operation;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) return true;
+		if (o == null || getClass() != o.getClass()) return false;
+
+		ConfigChangeListener that = (ConfigChangeListener) o;
+
+		if (!keys.equals(that.keys)) return false;
+		return operation.equals(that.operation);
+	}
+
+	@Override
+	public int hashCode() {
+		int result = keys.hashCode();
+		result = 31 * result + operation.hashCode();
+		return result;
+	}
+}

rapidoid-commons/src/main/java/org/rapidoid/config/ConfigChanges.java

@@ -0,0 +1,108 @@
+package org.rapidoid.config;
+
+import org.rapidoid.RapidoidThing;
+import org.rapidoid.annotation.Authors;
+import org.rapidoid.annotation.Since;
+import org.rapidoid.collection.Coll;
+import org.rapidoid.u.U;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+/*
+ * #%L
+ * rapidoid-commons
+ * %%
+ * Copyright (C) 2014 - 2016 Nikolche Mihajlovski and contributors
+ * %%
+ * 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.
+ * #L%
+ */
+
+@Authors("Nikolche Mihajlovski")
+@Since("5.3.0")
+public class ConfigChanges extends RapidoidThing {
+
+	public final boolean initial;
+
+	public final Map<String, Object> added = Coll.synchronizedMap();
+
+	public final Map<String, Object> changed = Coll.synchronizedMap();
+
+	public final Set<String> removed = Coll.synchronizedSet();
+
+	public final List<String> keys = Coll.synchronizedList();
+
+	private ConfigChanges(boolean initial) {
+		this.initial = initial;
+	}
+
+	public static ConfigChanges from(List<String> keys, Map<String, Object> old, Map<String, Object> fresh, boolean initial) {
+
+		ConfigChanges changes = new ConfigChanges(initial);
+
+		Coll.assign(changes.keys, keys);
+
+		for (Map.Entry<String, Object> e : old.entrySet()) {
+
+			String key = e.getKey();
+			Object oldValue = e.getValue();
+			Object newValue = fresh.get(key);
+
+			if (newValue != null) {
+				if (U.neq(oldValue, newValue)) {
+					changes.changed.put(key, newValue);
+				}
+			} else {
+				changes.removed.add(key);
+			}
+		}
+
+		for (Map.Entry<String, Object> e : fresh.entrySet()) {
+
+			String key = e.getKey();
+			Object newValue = fresh.get(key);
+
+			if (!old.containsKey(key)) {
+				changes.added.put(key, newValue);
+			}
+		}
+
+		return changes;
+	}
+
+	public int count() {
+		return added.size() + changed.size() + removed.size();
+	}
+
+	public <T> Map<String, T> added(Class<T> type) {
+		return Coll.toBeanMap(added, type);
+	}
+
+	public <T> Map<String, T> changed(Class<T> type) {
+		return Coll.toBeanMap(changed, type);
+	}
+
+	@Override
+	public String toString() {
+		return "ConfigChanges{" +
+			"initial=" + initial +
+			", added=" + added +
+			", changed=" + changed +
+			", removed=" + removed +
+			", keys=" + keys +
+			'}';
+	}
+
+}