/*
* 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.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
/**
* Default implementation of a model factory extension point.
*
* @version $Rev: 898590 $ $Date: 2010-01-12 17:00:58 -0800 (Tue, 12 Jan 2010) $
*/
public class DefaultFactoryExtensionPoint implements FactoryExtensionPoint {
private ExtensionPointRegistry registry;
private Map<Class<?>, Object> factories = new ConcurrentHashMap<Class<?>, Object>();
/**
* Constructs a new DefaultModelFactoryExtensionPoint.
*/
public DefaultFactoryExtensionPoint(ExtensionPointRegistry extensionPointRegistry) {
this.registry = 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 =
registry.getServiceDiscovery().getServiceDeclaration(factoryInterface);
if (factoryDeclaration != null) {
try {
// Constructor taking the extension point registry
factory = newInstance(registry, 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);
}
}
}