/*
 *
 * Copyright 2002 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 * 
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 
 * - Redistribution in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY
 * DAMAGES OR LIABILITIES SUFFERED BY LICENSEE AS A RESULT OF OR
 * RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THIS SOFTWARE OR
 * ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE
 * FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT,
 * SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF
 * THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS
 * BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that this software is not designed, licensed or
 * intended for use in the design, construction, operation or
 * maintenance of any nuclear facility.
 * 
 */
/**
 * The SimpleTopicSubscriber class consists only of a main
 * method, which receives one or more messages from a topic using
 * asynchronous message delivery.  It uses the message listener
 * TextListener.  Run this program in conjunction with
 * SimpleTopicPublisher.  
 *
 * Specify a topic name on the command line when you run the 
 * program. To end the program, enter Q or q on the command line.
 */
import javax.jms.*;
import javax.naming.*;
import java.io.*;

public class SimpleTopicSubscriber {

    /**
     * Main method.
     *
     * @param args     the topic used by the example
     */
    public static void main(String[] args) {
        String                  topicName = null;
        Context                 jndiContext = null;
        TopicConnectionFactory  topicConnectionFactory = null;
        TopicConnection         topicConnection = null;
        TopicSession            topicSession = null;
        Topic                   topic = null;
        TopicSubscriber         topicSubscriber = null;
        TextListener            topicListener = null;
        TextMessage             message = null;
        InputStreamReader       inputStreamReader = null;
        char                    answer = '\0';
                
        /*
         * Read topic name from command line and display it.
         */
        if (args.length != 1) {
            System.out.println("Usage: java " +
                "SimpleTopicSubscriber <topic-name>");
            System.exit(1);
        }
        topicName = new String(args[0]);
        System.out.println("Topic name is " + topicName);

        /* 
         * 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 does
         * not exist, exit.
         */
        try {
            topicConnectionFactory = (TopicConnectionFactory)
                jndiContext.lookup("TopicConnectionFactory");
            topic = (Topic) jndiContext.lookup(topicName);
        } 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);
            topicListener = new TextListener();
            topicSubscriber.setMessageListener(topicListener);
            topicConnection.start();
            System.out.println("To end program, enter Q or q, " +
                "then <return>");
            inputStreamReader = new InputStreamReader(System.in);
            while (!((answer == 'q') || (answer == 'Q'))) {
                try {
                    answer = (char) inputStreamReader.read();
                } catch (IOException e) {
                    System.out.println("I/O exception: " 
                        + e.toString());
                }
            }
        } catch (JMSException e) {
            System.out.println("Exception occurred: " +
                e.toString());
        } finally {
            if (topicConnection != null) {
                try {
                    topicConnection.close();
                } catch (JMSException e) {}
            }
        }
    }
}