/**
* Copyright (C) 2011 Brian Ferris <bdferris@onebusaway.org>
*
* Licensed 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.onebusaway.federations;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.HashMap;
import java.util.Map;
import org.onebusaway.federations.annotations.FederatedServiceMethodInvocationHandler;
import org.onebusaway.federations.annotations.FederatedServiceMethodInvocationHandlerFactory;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.config.AbstractFactoryBean;
/**
* A Spring {@link FactoryBean} for creating a proxied service interface that
* virtually dispatches to a set of {@link FederatedService} instances, as
* contained by a {@link FederatedServiceCollection}.
*
* <pre class="code">
* <bean class="org.onebusaway.federations.FederatedServiceFactoryBean">
* <property name="serviceInterface" value="some.package.SomeServiceInterface"/>
* <proeprty name="collection" ref="federatedServiceCollectionImpl" />
* </bean>
* </pre>
*
* @author bdferris
* @see FederatedService
* @see FederatedServiceCollection
*/
public class FederatedServiceFactoryBean extends AbstractFactoryBean<Object> {
private static FederatedServiceMethodInvocationHandlerFactory _handlerFactory = new FederatedServiceMethodInvocationHandlerFactory();
private Class<?> _serviceInterface;
private FederatedServiceCollection _collection;
public void setServiceInterface(Class<?> serviceInterface) {
_serviceInterface = serviceInterface;
}
public void setCollection(FederatedServiceCollection collection) {
_collection = collection;
}
@Override
public Class<?> getObjectType() {
return _serviceInterface;
}
@Override
protected Object createInstance() throws Exception {
if (!_serviceInterface.isInterface())
throw new IllegalArgumentException("service "
+ _serviceInterface.getName() + " is not an interface");
if (!FederatedService.class.isAssignableFrom(_serviceInterface))
throw new IllegalArgumentException("service interface "
+ _serviceInterface.getName() + " does not implement "
+ FederatedService.class);
Map<Method, FederatedServiceMethodInvocationHandler> methodHandlers = getMethodHandlers();
FederatedServiceInvocationHandler handler = new FederatedServiceInvocationHandler(
methodHandlers, _collection);
Class<?>[] interfaces = {_serviceInterface};
return Proxy.newProxyInstance(_serviceInterface.getClassLoader(),
interfaces, handler);
}
private Map<Method, FederatedServiceMethodInvocationHandler> getMethodHandlers() {
Map<Method, FederatedServiceMethodInvocationHandler> handlers = new HashMap<Method, FederatedServiceMethodInvocationHandler>();
for (Method method : _serviceInterface.getDeclaredMethods()) {
FederatedServiceMethodInvocationHandler handler = _handlerFactory.getHandlerForMethod(method);
handlers.put(method, handler);
}
return handlers;
}
}