com.athena.sqs.MessageReceiveListener.java Source code

Introduction

Here is the source code for com.athena.sqs.MessageReceiveListener.java

Source

/*
 * Copyright 2012 The Athena Project
 *
 * The Athena Project licenses this file to you 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 com.athena.sqs;

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.WebApplicationContext;

/**
 * This class is a ContextListener for SQS receiver module.
 * Queue name must be in web.xml configuration and start listen from amazon SQS.
 *
 * @author Ji-Woong Choi(ienvyou@gmail.com)
 *
 */
public class MessageReceiveListener implements ServletContextListener {
    private final Logger logger = LoggerFactory.getLogger(getClass());

    private MessageReceiver receiver;
    private String listenQueueName;

    public void contextInitialized(ServletContextEvent sce) {
        ServletContext servletContext = sce.getServletContext();
        listenQueueName = servletContext.getInitParameter("listenQueueName");
        if (listenQueueName == null) {
            listenQueueName = "your_listen_queue_name";
        }

        ApplicationContext applicationContext = (ApplicationContext) servletContext
                .getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
        receiver = applicationContext.getBean(MessageReceiver.class);

        // If you want to run multiple receivers, create tasks or change doReceive method to async.
        /*
         * List<BizQueue> list = dao.getBizQueueList();
         * for(BizQueue queue : list) {
         *     BizQueueTask task = new BiaQueueTask(sqsContext, queue);
         *     task.run(); // thread start.
         * }
         */
        try {
            logger.debug("***********************************************");
            logger.debug("SQS Message Receiver is starting");
            logger.debug("***********************************************");

            // Queue names are loaded from sqsContext.xml

            List<String> queueList = (List<String>) applicationContext.getBean("initialQueueList");

            for (String queueName : queueList) {
                receiver.doReceive(queueName);
                Thread.sleep(2000);
            }

            // Default listen queue start
            receiver.doReceive(listenQueueName);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void contextDestroyed(ServletContextEvent arg0) {
        // TODO Auto-generated method stub
        if (receiver != null) {
            try {
                receiver.doDisconnect();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

}