Java tutorial
/* * Copyright (c) 2017, WSO2 Inc. (http://www.wso2.org) All Rights Reserved. * * WSO2 Inc. 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.wso2.siddhi.extension.output.transport.jms.util; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.util.Enumeration; import java.util.HashMap; import java.util.Map; import javax.jms.Destination; import javax.jms.JMSException; import javax.jms.MapMessage; import javax.jms.Message; import javax.jms.MessageConsumer; import javax.jms.QueueConnection; import javax.jms.QueueConnectionFactory; import javax.jms.Session; import javax.jms.TextMessage; public class QueueConsumer implements Runnable { private QueueConnectionFactory queueConnectionFactory; private String queueName; private boolean active = true; private static Log log = LogFactory.getLog(QueueConsumer.class); public QueueConsumer(QueueConnectionFactory queueConnectionFactory, String queueName) { this.queueConnectionFactory = queueConnectionFactory; this.queueName = queueName; } public void run() { // create queue connection QueueConnection queueConnection = null; try { queueConnection = queueConnectionFactory.createQueueConnection(); queueConnection.start(); } catch (JMSException e) { log.error("Can not create queue connection." + e.getMessage(), e); return; } Session session; try { session = queueConnection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE); Destination destination = session.createQueue(queueName); MessageConsumer consumer = session.createConsumer(destination); log.info("Listening for messages at " + queueName); while (active) { Message message = consumer.receive(1000); if (message != null) { if (message instanceof MapMessage) { MapMessage mapMessage = (MapMessage) message; Map<String, Object> map = new HashMap<String, Object>(); Enumeration enumeration = mapMessage.getMapNames(); while (enumeration.hasMoreElements()) { String key = (String) enumeration.nextElement(); map.put(key, mapMessage.getObject(key)); } log.info("Received Map Message: " + map); } else if (message instanceof TextMessage) { log.info("Received Text Message: " + ((TextMessage) message).getText()); } else { log.info("Received message: " + message.toString()); } } } log.info("Finished listening for messages."); session.close(); queueConnection.stop(); queueConnection.close(); } catch (JMSException e) { log.error("Can not subscribe." + e.getMessage(), e); } } public void shutdown() { active = false; } }