1 files changed, 118 insertions, 0 deletions
diff --git a/sca-java-1.x/tags/1.6-TUSCANY-3909/contribution/src/main/java/org/apache/tuscany/sca/contribution/service/DefaultContributionListenerExtensionPoint.java b/sca-java-1.x/tags/1.6-TUSCANY-3909/contribution/src/main/java/org/apache/tuscany/sca/contribution/service/DefaultContributionListenerExtensionPoint.java
new file mode 100644
index 0000000000..1ab80e344b
--- /dev/null
+++ b/sca-java-1.x/tags/1.6-TUSCANY-3909/contribution/src/main/java/org/apache/tuscany/sca/contribution/service/DefaultContributionListenerExtensionPoint.java
@@ -0,0 +1,118 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.apache.tuscany.sca.contribution.service;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+import org.apache.tuscany.sca.extensibility.ServiceDiscovery;
+
+/**
+ * Default implementation of a contribution listener extension point.
+ *
+ * @version $Rev$ $Date$
+ */
+public class DefaultContributionListenerExtensionPoint implements ContributionListenerExtensionPoint {
+    
+    private List<ContributionListener> listeners = new CopyOnWriteArrayList<ContributionListener>();
+    private boolean loadedListeners;
+    private ModelFactoryExtensionPoint modelFactories;
+    
+    /**
+     * Constructs a new DefaultContributionListenerExtensionPoint.
+     *  
+     */
+    public DefaultContributionListenerExtensionPoint(ModelFactoryExtensionPoint modelFactories) {
+        this.modelFactories = modelFactories;
+    }
+
+    /**
+     * Constructs a new DefaultContributionListenerExtensionPoint.
+     *  
+     */
+    public DefaultContributionListenerExtensionPoint(ExtensionPointRegistry extensionPoints) {
+        this.modelFactories = extensionPoints.getExtensionPoint(ModelFactoryExtensionPoint.class);
+    }
+
+    public void addContributionListener(ContributionListener listener) {
+        listeners.add(listener);
+    }
+
+    public List<ContributionListener> getContributionListeners() {
+        loadListeners();
+        return listeners;
+    }
+
+    public void removeContributionListener(ContributionListener listener) {
+        listeners.remove(listener);
+    }
+
+    /**
+     * Dynamically load listeners declared under META-INF/services
+     */
+    @SuppressWarnings("unchecked")
+    private synchronized void loadListeners() {
+        if (loadedListeners)
+            return;
+
+        // Get the listener service declarations
+        Set<ServiceDeclaration> listenerDeclarations; 
+        try {
+            listenerDeclarations = ServiceDiscovery.getInstance().getServiceDeclarations(ContributionListener.class);
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+        
+        // Load and instantiate the listeners
+        for (ServiceDeclaration listenerDeclaration: listenerDeclarations) {
+            ContributionListener listener;
+            try {
+                Class<ContributionListener> listenerClass = (Class<ContributionListener>)listenerDeclaration.loadClass();
+                try {
+                    Constructor<ContributionListener> constructor = listenerClass.getConstructor(ModelFactoryExtensionPoint.class);
+                    try {
+                        listener = constructor.newInstance(modelFactories);
+                    } catch (InvocationTargetException e) {
+                        throw new IllegalArgumentException(e);
+                    }
+                } catch (NoSuchMethodException e) {
+                    listener = listenerClass.newInstance();
+                }
+            } catch (ClassNotFoundException e) {
+                throw new IllegalArgumentException(e);
+            } catch (InstantiationException e) {
+                throw new IllegalArgumentException(e);
+            } catch (IllegalAccessException e) {
+                throw new IllegalArgumentException(e);
+            }
+            addContributionListener(listener);
+        }
+        
+        loadedListeners = true;
+    }
+
+}