From 6f41ef61af2268d5576448974ca447b597387e88 Mon Sep 17 00:00:00 2001 From: antelder Date: Tue, 16 Jun 2009 06:48:13 +0000 Subject: Create 2.0 M3 release branch git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@785089 13f79535-47bb-0310-9956-ffa450edef68 --- .../sca/core/DefaultExtensionPointRegistry.java | 226 +++++++++++++++++++++ 1 file changed, 226 insertions(+) create mode 100644 branches/sca-java-2.0-M3/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultExtensionPointRegistry.java (limited to 'branches/sca-java-2.0-M3/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultExtensionPointRegistry.java') diff --git a/branches/sca-java-2.0-M3/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultExtensionPointRegistry.java b/branches/sca-java-2.0-M3/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultExtensionPointRegistry.java new file mode 100644 index 0000000000..3ea587c5f2 --- /dev/null +++ b/branches/sca-java-2.0-M3/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultExtensionPointRegistry.java @@ -0,0 +1,226 @@ +/* + * 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.core; + +import java.io.IOException; +import java.lang.reflect.Constructor; +import java.lang.reflect.InvocationTargetException; +import java.lang.reflect.Modifier; +import java.util.HashMap; +import java.util.HashSet; +import java.util.IdentityHashMap; +import java.util.Map; +import java.util.Set; + +import org.apache.tuscany.sca.extensibility.ServiceDeclaration; +import org.apache.tuscany.sca.extensibility.ServiceDiscovery; + +/** + * Default implementation of a registry to hold all the Tuscany core extension + * points. As the point of contact for all extension artifacts this registry + * allows loaded extensions to find all other parts of the system and register + * themselves appropriately. + * + * @version $Rev$ $Date$ + */ +public class DefaultExtensionPointRegistry implements ExtensionPointRegistry { + private Map, Object> extensionPoints = new HashMap, Object>(); + + /** + * Constructs a new registry. + */ + public DefaultExtensionPointRegistry() { + } + + /** + * Add an extension point to the registry. This default implementation + * stores extensions against the interfaces that they implement. + * + * @param extensionPoint The instance of the extension point + * + * @throws IllegalArgumentException if extensionPoint is null + */ + public synchronized void addExtensionPoint(Object extensionPoint) { + addExtensionPoint(extensionPoint, null); + } + + public synchronized void addExtensionPoint(Object extensionPoint, ServiceDeclaration declaration) { + if (extensionPoint == null) { + throw new IllegalArgumentException("Cannot register null as an ExtensionPoint"); + } + if (extensionPoint instanceof ModuleActivator) { + ((ModuleActivator)extensionPoint).start(this); + } + Set> interfaces = getAllInterfaces(extensionPoint.getClass()); + for (Class i : interfaces) { + registerExtensionPoint(i, extensionPoint, declaration); + } + } + + protected void registerExtensionPoint(Class i, Object extensionPoint, ServiceDeclaration declaration) { + extensionPoints.put(i, extensionPoint); + } + + private Constructor getConstructor(Constructor[] constructors, Class[] paramTypes) { + for (Constructor c : constructors) { + Class[] types = c.getParameterTypes(); + if (c.getParameterTypes().length == paramTypes.length) { + boolean found = true; + for (int i = 0; i < types.length; i++) { + if (types[i] != paramTypes[i]) { + found = false; + break; + } + } + if (found) { + return c; + } + } + } + return null; + } + + /** + * Get the extension point by the interface that it implements + * + * @param extensionPointType The lookup key (extension point interface) + * @return The instance of the extension point + * + * @throws IllegalArgumentException if extensionPointType is null + */ + public synchronized T getExtensionPoint(Class extensionPointType) { + if (extensionPointType == null) { + throw new IllegalArgumentException("Cannot lookup ExtensionPoint of type null"); + } + + Object extensionPoint = findExtensionPoint(extensionPointType); + if (extensionPoint == null) { + + // Dynamically load an extension point class declared under META-INF/services + try { + ServiceDeclaration extensionPointDeclaration = + ServiceDiscovery.getInstance().getServiceDeclaration(extensionPointType.getName()); + if (extensionPointDeclaration != null) { + Class extensionPointClass = extensionPointDeclaration.loadClass(); + + // Construct the extension point + Constructor[] constructors = extensionPointClass.getConstructors(); + Constructor constructor = + getConstructor(constructors, new Class[] {ExtensionPointRegistry.class}); + if (constructor != null) { + extensionPoint = constructor.newInstance(this); + } else { + constructor = getConstructor(constructors, new Class[] {}); + if (constructor != null) { + extensionPoint = constructor.newInstance(); + } else { + throw new IllegalArgumentException( + "No valid constructor is found for " + extensionPointClass); + } + } + + // Cache the loaded extension point + addExtensionPoint(extensionPoint, extensionPointDeclaration); + } + } catch (InvocationTargetException e) { + throw new IllegalArgumentException(e); + } catch (IOException e) { + throw new IllegalArgumentException(e); + } catch (ClassNotFoundException e) { + throw new IllegalArgumentException(e); + } catch (InstantiationException e) { + throw new IllegalArgumentException(e); + } catch (IllegalAccessException e) { + throw new IllegalArgumentException(e); + } + } + return extensionPointType.cast(extensionPoint); + } + + protected Object findExtensionPoint(Class extensionPointType) { + return extensionPoints.get(extensionPointType); + } + + /** + * Remove an extension point based on the interface that it implements + * + * @param extensionPoint The extension point to remove + * + * @throws IllegalArgumentException if extensionPoint is null + */ + public synchronized void removeExtensionPoint(Object extensionPoint) { + if (extensionPoint == null) { + throw new IllegalArgumentException("Cannot remove null as an ExtensionPoint"); + } + + if (extensionPoint instanceof ModuleActivator) { + ((ModuleActivator)extensionPoint).stop(this); + } + + Set> interfaces = getAllInterfaces(extensionPoint.getClass()); + for (Class i : interfaces) { + unregisterExtensionPoint(i); + } + } + + protected void unregisterExtensionPoint(Class i) { + extensionPoints.remove(i); + } + + /** + * Returns the set of interfaces implemented by the given class and its + * ancestors or a blank set if none + */ + private static Set> getAllInterfaces(Class clazz) { + Set> implemented = new HashSet>(); + getAllInterfaces(clazz, implemented); + return implemented; + } + + private static void getAllInterfaces(Class clazz, Set> implemented) { + Class[] interfaces = clazz.getInterfaces(); + for (Class interfaze : interfaces) { + if (Modifier.isPublic(interfaze.getModifiers())) { + implemented.add(interfaze); + } + } + Class superClass = clazz.getSuperclass(); + // Object has no superclass so check for null + if (superClass != null && !superClass.equals(Object.class)) { + getAllInterfaces(superClass, implemented); + } + } + + public void destroy() { + // Get a unique map as an extension point may exist in the map by different keys + Map map = new IdentityHashMap(); + for (Object extp : extensionPoints.values()) { + if (extp instanceof ModuleActivator) { + ModuleActivator activator = (ModuleActivator)extp; + map.put(activator, activator); + } + } + for (ModuleActivator activator : map.values()) { + activator.stop(this); + } + extensionPoints.clear(); + } + +} -- cgit v1.2.3