asynchconsumer.java

JavaeeTutorial5的源代码。

/*
 * Copyright 2007 Sun Microsystems, Inc.
 * All rights reserved.  You may not modify, use,
 * reproduce, or distribute this software except in
 * compliance with  the terms of the License at:
 * http://developer.sun.com/berkeley_license.html
 */


import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.Queue;
import javax.jms.Topic;
import javax.jms.Connection;
import javax.jms.Session;
import javax.jms.MessageConsumer;
import javax.jms.TextMessage;
import javax.jms.JMSException;
import javax.annotation.Resource;
import java.io.InputStreamReader;
import java.io.IOException;


/**
 * The AsynchConsumer class consists only of a main
 * method, which receives one or more messages from a queue or
 * topic using asynchronous message delivery.  It uses the
 * message listener TextListener.  Run this program in
 * conjunction with Producer.
 *
 * Specify "queue" or "topic" name on the command line when you run
 * the program. To end the program, type Q or q on the command
 * line.
 */
public class AsynchConsumer {
    @Resource(mappedName = "jms/ConnectionFactory")
    private static ConnectionFactory connectionFactory;
    @Resource(mappedName = "jms/Queue")
    private static Queue queue;
    @Resource(mappedName = "jms/Topic")
    private static Topic topic;

    /**
     * Main method.
     *
     * @param args     the destination name and type used by the
     *                 example
     */
    public static void main(String[] args) {
        String destType = null;
        Connection connection = null;
        Session session = null;
        Destination dest = null;
        MessageConsumer consumer = null;
        TextListener listener = null;
        TextMessage message = null;
        InputStreamReader inputStreamReader = null;
        char answer = '\0';

        if (args.length != 1) {
            System.err.println("Program takes one argument: <dest_type>");
            System.exit(1);
        }

        destType = args[0];
        System.out.println("Destination type is " + destType);

        if (!(destType.equals("queue") || destType.equals("topic"))) {
            System.err.println("Argument must be \"queue\" or \"topic\"");
            System.exit(1);
        }

        try {
            if (destType.equals("queue")) {
                dest = (Destination) queue;
            } else {
                dest = (Destination) topic;
            }
        } catch (Exception e) {
            System.err.println("Error setting destination: " + e.toString());
            e.printStackTrace();
            System.exit(1);
        }

        /*
         * Create connection.
         * Create session from connection; false means session is
         * not transacted.
         * Create consumer.
         * Register message listener (TextListener).
         * Receive text messages from destination.
         * When all messages have been received, type Q to quit.
         * Close connection.
         */
        try {
            connection = connectionFactory.createConnection();
            session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
            consumer = session.createConsumer(dest);
            listener = new TextListener();
            consumer.setMessageListener(listener);
            connection.start();
            System.out.println(
                    "To end program, type Q or q, " + "then <return>");
            inputStreamReader = new InputStreamReader(System.in);

            while (!((answer == 'q') || (answer == 'Q'))) {
                try {
                    answer = (char) inputStreamReader.read();
                } catch (IOException e) {
                    System.err.println("I/O exception: " + e.toString());
                }
            }
        } catch (JMSException e) {
            System.err.println("Exception occurred: " + e.toString());
        } finally {
            if (connection != null) {
                try {
                    connection.close();
                } catch (JMSException e) {
                }
            }
        }
    }
}