feat(ObservableObjectMap): Added ObservableObjectMap

maps/src/main/java/com/georgev22/library/maps/ObservableObjectMap.java

@@ -0,0 +1,33 @@
+package com.georgev22.library.maps;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ObservableObjectMap<K, V> extends ConcurrentObjectMap<K, V> implements ObjectMap<K, V> {
+
+    private List<MapChangeListener<K, V>> listeners = new ArrayList<>();
+
+    public void addListener(MapChangeListener<K, V> listener) {
+        listeners.add(listener);
+    }
+
+    @Override
+    public V put(@NotNull K key, @NotNull V value) {
+        V oldValue = super.put(key, value);
+        fireEntryAddedEvent(key, value);
+        return oldValue;
+    }
+
+    private void fireEntryAddedEvent(K key, V value) {
+        for (MapChangeListener<K, V> listener : listeners) {
+            listener.entryAdded(key, value);
+        }
+    }
+
+    public interface MapChangeListener<K, V> {
+        void entryAdded(K key, V value);
+    }
+
+}