/*------------------------------------------------------------------------------
 *
 *  Boeing-Autometric, Inc.
 *
 *  Copyright (c) 2002 Boeing-Autometric, Inc.  All rights reserved.  This
 *  program or documentation contains proprietary confidential information and
 *  trade secrets of Autometric.  Reverse engineering of object code is
 *  prohibited.  Use of copyright notice is precautionary and does not imply
 *  publication.  Any unauthorized use, reproduction or transfer of this
 *  program is strictly prohibited.
 *
 *  RESTRICTED RIGHTS NOTICE
 *
 *  Use, duplication, or disclosure by the Government is subject to
 *  restrictions as set forth in subdivision (b)(3)(ii) of the Rights in
 *  Technical Data and Computer Software clause at 252.227-7013.
 *
 *  Autometric, Inc.
 *  1330 Inverness Drive, Suite 350
 *  Colorado Springs, CO 80910
 *  (719) 637-8332
 *
 *----------------------------------------------------------------------------*/
import javax.jms.*;

import javax.naming.*;

import java.io.*;


/**
 * Class SimpleTopicSubscriber
 *
 *
 * @author <a href="mailto:cbeaudin@cs.autometric.com">Chad Beaudin</a>
 * @version 1.0, $date$
 */
public class MyTopicSubscriber implements MessageListener {
    private float previousTime = 0;
    private float currentTime = 0;
    /**
     * Constructor MyTopicSubscriber
     *
     *
     * @param topicName
     *
     */
    public MyTopicSubscriber(String topicName) {

        Context                jndiContext            = null;
        TopicConnectionFactory topicConnectionFactory = null;
        TopicConnection        topicConnection        = null;
        TopicSession           topicSession           = null;
        Topic                  topic                  = null;
        TopicSubscriber        topicSubscriber        = null;

        previousTime  = System.currentTimeMillis();

        /*
        * Create a JNDI API InitialContext object if none exists yet.
        *
        */
        try {
            jndiContext = new InitialContext();
        } catch (NamingException e) {
            System.out.println("Could not create JNDI API " + "context: " + e.toString());
            e.printStackTrace();
            System.exit(1);
        }

        /*
         * Look up connection factory and topic.  If either doe snot exist, exit.
         *
         */
        try {
            topicConnectionFactory = (TopicConnectionFactory) jndiContext.lookup("TopicConnectionFactory");
            topic                  = (Topic) jndiContext.lookup(topicName);

            System.out.println("JNDI API lookup done");
        } catch (NamingException e) {
            System.out.println("JNDI API lookup failed: " + e.toString());
            e.printStackTrace();
            System.exit(1);
        }

        /*
         * Create connection.
         * Create session from connection; false means session is
         * not transacted.
         * Create subscriber.
         * Register message listener (TextListener).
         * Receive text messages from topic.
         * When all messages have been received, enter Q to quit.
         * Close connection.
         */
        try {
            topicConnection = topicConnectionFactory.createTopicConnection();
            topicSession    = topicConnection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
            topicSubscriber = topicSession.createSubscriber(topic);

            System.out.println("Subscribed to " + topicName);
            topicSubscriber.setMessageListener(this);
            topicConnection.start();
            System.out.println("Subscriber Started");
        } catch (JMSException e) {
            System.out.println("Exception occurred: " + e.toString());
        }
    }

    /**
     * This method is required when your class implements MessageListener.  This is the method
     * that will receive the updates from the topic.
     *
     *
     * @param message
     *
     */
    public void onMessage(Message message) {

        TextMessage msg = null;
        currentTime  = System.currentTimeMillis();

        try {
            if (message instanceof TextMessage) {
                msg = (TextMessage) message;
                System.out.println("Receiving message: " + msg.getText());
            } else {
                System.out.println("Message of wrong type: " + message.getClass().getName());
            }
        } catch (JMSException e) {
            System.out.println("JMSException in onMessage(): " + e.toString());
        } catch (Throwable t) {
            System.out.println("Exception in onMessage():" + t.getMessage());
        }
    }

    /**
     * Method main
     *
     *
     * @param args
     *
     */
    public static void main(String[] args) {

        String topicName = null;

        for (int i = 0; i < args.length; i++) {
            if (args[i].startsWith("-topic")) {
                topicName = args[i].substring(args[i].indexOf('=') + 1);
            } else {
                System.out.println("VALID USAGE\n-----------------------------");
                System.out.println("-topic=\"your topic\"");
                System.exit(1);
            }
        }

        //Create the topic subscriber
        MyTopicSubscriber subscriber = new MyTopicSubscriber(topicName);
    }
}