| /* |
| * 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.aries.proxy.impl; |
| |
| import java.lang.reflect.InvocationHandler; |
| import java.lang.reflect.InvocationTargetException; |
| import java.lang.reflect.Method; |
| import java.util.concurrent.Callable; |
| |
| import org.apache.aries.proxy.InvocationListener; |
| |
| public final class ProxyHandler implements InvocationHandler { |
| private final Callable<Object> target; |
| private final InvocationHandler core; |
| private final AbstractProxyManager proxyManager; |
| |
| public ProxyHandler(AbstractProxyManager abstractProxyManager, Callable<Object> dispatcher, InvocationListener listener) |
| { |
| target = dispatcher; |
| proxyManager = abstractProxyManager; |
| final InvocationListener nonNullListener; |
| if (listener == null) { |
| nonNullListener = new DefaultWrapper(); |
| } else { |
| nonNullListener = listener; |
| } |
| |
| core = new InvocationHandler() { |
| public Object invoke(Object proxy, Method method, Object[] args) |
| throws Throwable |
| { |
| Object result = null; |
| Object token = null; |
| boolean inInvoke = false; |
| try { |
| token = nonNullListener.preInvoke(proxy, method, args); |
| inInvoke = true; |
| result = nonNullListener.aroundInvoke(token, proxy, target, method, args); |
| inInvoke = false; |
| nonNullListener.postInvoke(token, proxy, method, result); |
| |
| } catch (Throwable e) { |
| // whether the the exception is an error is an application decision |
| // if we catch an exception we decide carefully which one to |
| // throw onwards |
| Throwable exceptionToRethrow = null; |
| // if the exception came from a precall or postcall |
| // we will rethrow it |
| if (!inInvoke) { |
| exceptionToRethrow = e; |
| } |
| // if the exception didn't come from precall or postcall then it |
| // came from invoke |
| // we will rethrow this exception if it is not a runtime |
| // exception, but we must unwrap InvocationTargetExceptions |
| else { |
| if (e instanceof InvocationTargetException) { |
| e = ((InvocationTargetException) e).getTargetException(); |
| } |
| |
| if (!(e instanceof RuntimeException)) { |
| exceptionToRethrow = e; |
| } |
| } |
| try { |
| nonNullListener.postInvokeExceptionalReturn(token, proxy, method, e); |
| } catch (Exception f) { |
| // we caught an exception from |
| // postInvokeExceptionalReturn |
| // if we haven't already chosen an exception to rethrow then |
| // we will throw this exception |
| if (exceptionToRethrow == null) { |
| exceptionToRethrow = f; |
| } |
| } |
| // if we made it this far without choosing an exception we |
| // should throw e |
| if (exceptionToRethrow == null) { |
| exceptionToRethrow = e; |
| } |
| throw exceptionToRethrow; |
| } |
| return result; |
| } |
| }; |
| } |
| |
| public Object invoke(Object proxy, Method method, Object[] args) throws Throwable |
| { |
| // Unwrap calls for equals |
| if (method.getName().equals("equals") |
| && method.getParameterTypes().length == 1 && |
| method.getParameterTypes()[0] == Object.class) { |
| Object targetObject = args[0]; |
| if (proxyManager.isProxy(targetObject)) { |
| args[0] = proxyManager.unwrap(targetObject).call(); |
| } |
| } else if (method.getName().equals("finalize") && method.getParameterTypes().length == 0) { |
| // special case finalize, don't route through to delegate because that will get its own call |
| return null; |
| } |
| |
| return core.invoke(proxy, method, args); |
| } |
| |
| public Callable<Object> getTarget() |
| { |
| return target; |
| } |
| } |