| /** |
| * 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.activemq.ra; |
| |
| import java.lang.reflect.Method; |
| |
| import javax.jms.Message; |
| import javax.jms.MessageListener; |
| import javax.resource.ResourceException; |
| import javax.resource.spi.endpoint.MessageEndpoint; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * @author <a href="mailto:michael.gaffney@panacya.com">Michael Gaffney </a> |
| */ |
| public class MessageEndpointProxy implements MessageListener, MessageEndpoint { |
| |
| private static final MessageEndpointState ALIVE = new MessageEndpointAlive(); |
| private static final MessageEndpointState DEAD = new MessageEndpointDead(); |
| private static final Logger LOG = LoggerFactory.getLogger(MessageEndpointProxy.class); |
| |
| private static int proxyCount; |
| private final int proxyID; |
| |
| private final MessageEndpoint endpoint; |
| private final MessageListener messageListener; |
| private MessageEndpointState state = ALIVE; |
| |
| public MessageEndpointProxy(MessageEndpoint endpoint) { |
| if (!(endpoint instanceof MessageListener)) { |
| throw new IllegalArgumentException("MessageEndpoint is not a MessageListener"); |
| } |
| messageListener = (MessageListener)endpoint; |
| proxyID = getID(); |
| this.endpoint = endpoint; |
| } |
| |
| private static int getID() { |
| return ++proxyCount; |
| } |
| |
| public void beforeDelivery(Method method) throws NoSuchMethodException, ResourceException { |
| LOG.trace("Invoking MessageEndpoint.beforeDelivery()"); |
| state.beforeDelivery(this, method); |
| } |
| |
| public void onMessage(Message message) { |
| LOG.trace("Invoking MessageEndpoint.onMethod()"); |
| state.onMessage(this, message); |
| } |
| |
| public void afterDelivery() throws ResourceException { |
| LOG.trace("Invoking MessageEndpoint.afterDelivery()"); |
| state.afterDelivery(this); |
| } |
| |
| public void release() { |
| LOG.trace("Invoking MessageEndpoint.release()"); |
| state.release(this); |
| } |
| |
| public String toString() { |
| return "MessageEndpointProxy{ " + "proxyID: " + proxyID + ", endpoint: " + endpoint + " }"; |
| } |
| |
| private abstract static class MessageEndpointState { |
| |
| public void beforeDelivery(MessageEndpointProxy proxy, Method method) throws NoSuchMethodException, ResourceException { |
| throw new IllegalStateException(); |
| } |
| |
| public void onMessage(MessageEndpointProxy proxy, Message message) { |
| throw new IllegalStateException(); |
| } |
| |
| public void afterDelivery(MessageEndpointProxy proxy) throws ResourceException { |
| throw new IllegalStateException(); |
| } |
| |
| public void release(MessageEndpointProxy proxy) { |
| throw new IllegalStateException(); |
| } |
| |
| protected final void transition(MessageEndpointProxy proxy, MessageEndpointState nextState) { |
| proxy.state = nextState; |
| nextState.enter(proxy); |
| } |
| |
| protected void enter(MessageEndpointProxy proxy) { |
| } |
| } |
| |
| private static class MessageEndpointAlive extends MessageEndpointState { |
| |
| public void beforeDelivery(MessageEndpointProxy proxy, Method method) throws NoSuchMethodException, ResourceException { |
| try { |
| proxy.endpoint.beforeDelivery(method); |
| } catch (NoSuchMethodException e) { |
| transition(proxy, DEAD); |
| throw e; |
| } catch (ResourceException e) { |
| transition(proxy, DEAD); |
| throw e; |
| } |
| } |
| |
| public void onMessage(MessageEndpointProxy proxy, Message message) { |
| proxy.messageListener.onMessage(message); |
| } |
| |
| public void afterDelivery(MessageEndpointProxy proxy) throws ResourceException { |
| try { |
| proxy.endpoint.afterDelivery(); |
| } catch (ResourceException e) { |
| transition(proxy, DEAD); |
| throw e; |
| } |
| } |
| |
| public void release(MessageEndpointProxy proxy) { |
| transition(proxy, DEAD); |
| } |
| } |
| |
| private static class MessageEndpointDead extends MessageEndpointState { |
| |
| protected void enter(MessageEndpointProxy proxy) { |
| proxy.endpoint.release(); |
| } |
| |
| public void beforeDelivery(MessageEndpointProxy proxy, Method method) throws NoSuchMethodException, ResourceException { |
| throw new InvalidMessageEndpointException(); |
| } |
| |
| public void onMessage(MessageEndpointProxy proxy, Message message) { |
| throw new InvalidMessageEndpointException(); |
| } |
| |
| public void afterDelivery(MessageEndpointProxy proxy) throws ResourceException { |
| throw new InvalidMessageEndpointException(); |
| } |
| |
| public void release(MessageEndpointProxy proxy) { |
| throw new InvalidMessageEndpointException(); |
| } |
| } |
| } |