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Diffstat (limited to 'branches/sca-java-2.0-M4/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultFactoryExtensionPoint.java')
-rw-r--r-- | branches/sca-java-2.0-M4/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultFactoryExtensionPoint.java | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/branches/sca-java-2.0-M4/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultFactoryExtensionPoint.java b/branches/sca-java-2.0-M4/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultFactoryExtensionPoint.java new file mode 100644 index 0000000000..300acdc259 --- /dev/null +++ b/branches/sca-java-2.0-M4/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultFactoryExtensionPoint.java @@ -0,0 +1,162 @@ +/* + * 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 static org.apache.tuscany.sca.extensibility.ServiceHelper.newInstance; + +import java.lang.reflect.Method; +import java.lang.reflect.Modifier; +import java.security.AccessController; +import java.security.PrivilegedAction; +import java.util.HashMap; + +import org.apache.tuscany.sca.extensibility.ServiceDeclaration; +import org.apache.tuscany.sca.extensibility.ServiceDiscovery; + + + +/** + * Default implementation of a model factory extension point. + * + * @version $Rev$ $Date$ + */ +public class DefaultFactoryExtensionPoint implements FactoryExtensionPoint { + private ExtensionPointRegistry extensionPointRegistry; + private HashMap<Class<?>, Object> factories = new HashMap<Class<?>, Object>(); + + /** + * Constructs a new DefaultModelFactoryExtensionPoint. + */ + public DefaultFactoryExtensionPoint(ExtensionPointRegistry extensionPointRegistry) { + this.extensionPointRegistry = extensionPointRegistry; + } + + /** + * Add a model factory extension. + * + * @param factory The factory to add + */ + public void addFactory(Object factory) { + Class<?>[] interfaces = factory.getClass().getInterfaces(); + if (interfaces.length == 0) { + Class<?> sc = factory.getClass().getSuperclass(); + if (sc != Object.class) { + factories.put(sc, factory); + } + } else { + for (int i = 0; i<interfaces.length; i++) { + factories.put(interfaces[i], factory); + } + } + } + + /** + * Remove a model factory. + * + * @param factory The factory to remove + */ + public void removeFactory(Object factory) { + Class<?>[] interfaces = factory.getClass().getInterfaces(); + if (interfaces.length == 0) { + Class<?> sc = factory.getClass().getSuperclass(); + if (sc != Object.class) { + factories.remove(sc); + } + } else { + for (int i = 0; i<interfaces.length; i++) { + factories.remove(interfaces[i]); + } + } + } + + private ClassLoader setContextClassLoader(final ClassLoader classLoader) { + return AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() { + public ClassLoader run() { + ClassLoader tccl = Thread.currentThread().getContextClassLoader(); + if (classLoader != null) { + Thread.currentThread().setContextClassLoader(classLoader); + } + return tccl; + } + }); + } + + /** + * Get a factory implementing the given interface. + * @param factoryInterface The lookup key (factory interface) + * @return The factory + */ + public <T> T getFactory(Class<T> factoryInterface) { + Object factory = factories.get(factoryInterface); + if (factory == null) { + + // Dynamically load a factory class declared under META-INF/services + try { + ServiceDeclaration factoryDeclaration = + ServiceDiscovery.getInstance().getServiceDeclaration(factoryInterface); + if (factoryDeclaration != null) { + try { + // Constructor taking the extension point registry + factory = newInstance(extensionPointRegistry, factoryDeclaration); + } catch (NoSuchMethodException e) { + factory = newInstance(factoryDeclaration.loadClass(), FactoryExtensionPoint.class, this); + } + + // Cache the loaded factory + factories.put(factoryInterface, factory); + + return factoryInterface.cast(factory); + + } else { + + // If the input interface is an abstract class + if (!factoryInterface.isInterface() && Modifier.isAbstract(factoryInterface.getModifiers())) { + Method newInstanceMethod = factoryInterface.getDeclaredMethod("newInstance"); + ClassLoader tccl = setContextClassLoader(factoryInterface.getClassLoader()); + try { + + // Create a new instance + factory = newInstanceMethod.invoke(null); + + // Cache the factory + factories.put(factoryInterface, factory); + + return factoryInterface.cast(factory); + } catch (Exception e) { + // Sorry no factory found + return null; + } finally { + setContextClassLoader(tccl); + } + } else { + + // Sorry no factory found + return null; + } + } + } catch (Exception e) { + throw new IllegalArgumentException(e); + } + } else { + return factoryInterface.cast(factory); + } + } + +} |