/**
* 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 org.onebusaway.federations.annotations.FederatedServiceMethodInvocationHandler;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.HashMap;
import java.util.Map;
/**
* An {@link InvocationHandler} for use in a {@link Proxy} service that can
* create a virtual service interface instance that dispatches method calls to
* an appropriate {@link FederatedService} instance as queryed from a
* {@link FederatedServiceCollection}. Each method in the service interface must
* have a {@link FederatedServiceMethodInvocationHandler} that determines how
* the method invocation is resolved to a federated service instance.
*
* @author bdferris
*/
class FederatedServiceInvocationHandler implements InvocationHandler {
private Map<Method, FederatedServiceMethodInvocationHandler> _methodHandlers = new HashMap<Method, FederatedServiceMethodInvocationHandler>();
private FederatedServiceCollection _collection;
public FederatedServiceInvocationHandler(
Map<Method, FederatedServiceMethodInvocationHandler> methodHandlers,
FederatedServiceCollection collection) {
_methodHandlers = methodHandlers;
_collection = collection;
}
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
FederatedServiceMethodInvocationHandler methodHandler = _methodHandlers.get(method);
if (method.getDeclaringClass() == Object.class)
return method.invoke(this, args);
try {
return methodHandler.invoke(_collection, method, args);
} catch (Throwable ex) {
if (ex instanceof InvocationTargetException) {
InvocationTargetException ite = (InvocationTargetException) ex;
ex = ite.getTargetException();
}
throw ex;
}
}
}