ActiveMQ example source code file (TopicListener.java)

This example ActiveMQ source code file (TopicListener.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - ActiveMQ tags/keywords

activemqconnectionfactory, exception, exception, jmsexception, messageconsumer, messagelistener, received, string, string, textmessage, topic, topic, topiclistener, topiclistener, util

The ActiveMQ TopicListener.java source code

/**
 * 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.
 */
import java.util.Arrays;

import javax.jms.Connection;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageListener;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.jms.Topic;

import org.apache.activemq.ActiveMQConnectionFactory;

/**
 * Use in conjunction with TopicPublisher to test the performance of ActiveMQ
 * Topics.
 */
public class TopicListener implements MessageListener {

    private Connection connection;
    private MessageProducer producer;
    private Session session;
    private int count;
    private long start;
    private Topic topic;
    private Topic control;

    private String url = "tcp://localhost:61616";

    public static void main(String[] argv) throws Exception {
        TopicListener l = new TopicListener();
        String[] unknown = CommandLineSupport.setOptions(l, argv);
        if (unknown.length > 0) {
            System.out.println("Unknown options: " + Arrays.toString(unknown));
            System.exit(-1);
        }
        l.run();
    }

    public void run() throws JMSException {
        ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(url);
        connection = factory.createConnection();
        session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
        topic = session.createTopic("topictest.messages");
        control = session.createTopic("topictest.control");

        MessageConsumer consumer = session.createConsumer(topic);
        consumer.setMessageListener(this);

        connection.start();

        producer = session.createProducer(control);
        System.out.println("Waiting for messages...");
    }

    private static boolean checkText(Message m, String s) {
        try {
            return m instanceof TextMessage && ((TextMessage)m).getText().equals(s);
        } catch (JMSException e) {
            e.printStackTrace(System.out);
            return false;
        }
    }

    public void onMessage(Message message) {
        if (checkText(message, "SHUTDOWN")) {

            try {
                connection.close();
            } catch (Exception e) {
                e.printStackTrace(System.out);
            }

        } else if (checkText(message, "REPORT")) {
            // send a report:
            try {
                long time = System.currentTimeMillis() - start;
                String msg = "Received " + count + " in " + time + "ms";
                producer.send(session.createTextMessage(msg));
            } catch (Exception e) {
                e.printStackTrace(System.out);
            }
            count = 0;

        } else {

            if (count == 0) {
                start = System.currentTimeMillis();
            }

            if (++count % 1000 == 0) {
                System.out.println("Received " + count + " messages.");
            }
        }
    }

    public void setUrl(String url) {
        this.url = url;
    }

}