ackequivexample.java

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             * Look up connection factory and topic.  If either
             * does not exist, exit.
             */
            try {
                connectionFactory = 
                    SampleUtilities.getConnectionFactory(conFacName);
                connection = 
                    connectionFactory.createConnection();
                session = connection.createSession(false, 
                    Session.AUTO_ACKNOWLEDGE);
                System.out.println("SUBSCRIBER: Created " +
                    "auto-acknowledge session");
                topic = SampleUtilities.getTopic(topicName, 
                    session);
            } catch (Exception e) {
                System.err.println("Connection problem: " + 
                    e.toString());
                if (connection != null) {
                    try {
                        connection.close();
                    } catch (JMSException ee) {}
                }
                System.exit(1);
            }
            
            /*
             * Create auto-acknowledge subscriber.
             * Register message listener (TextListener).
             * Start message delivery.
             * Send synchronize message to publisher, then wait
             *   till all messages have arrived.
             * Listener displays the messages obtained.
             */
            try {
                subscriber = 
                    session.createDurableSubscriber(topic,
                        "AckSub");
                listener = new TextListener();
                subscriber.setMessageListener(listener);
                connection.start();

                // Let publisher know that subscriber is ready.
                try {
                    SampleUtilities.sendSynchronizeMessage("SUBSCRIBER: ",
                        CONTROL_QUEUE);
                } catch (Exception e) {
                    System.err.println("Queue probably " + 
                        "missing: " + e.toString());
                    if (connection != null) {
                        try {
                            connection.close();
                        } catch (JMSException ee) {}
                    }
                    System.exit(1);
                }

                /*
                 * Asynchronously process messages.
                 * Block until publisher issues a control message
                 * indicating end of publish stream.
                 */
                listener.monitor.waitTillDone();
                subscriber.close();
                session.unsubscribe("AckSub");
            } catch (JMSException e) {
                System.err.println("Exception occurred: " + 
                    e.toString());
            } finally {
                if (connection != null) {
                    try {
                        connection.close();
                    } catch (JMSException e) {}
                }
            }
        }
    }

    /**
     * The MultiplePublisher class creates a session in 
     * AUTO_ACKNOWLEDGE mode and publishes three messages 
     * to a topic. 
     */
    public class MultiplePublisher extends Thread {
        
        /**
         * Runs the thread.
         */
        public void run() {
            ConnectionFactory  connectionFactory = null;
            Connection         connection = null;
            Session            session = null;
            Topic              topic = null;
            MessageProducer    publisher = null;
            TextMessage        message = null;
            final int          NUMMSGS = 3;
            final String       MSG_TEXT = new String("Here is an auto-acknowledge message");

            try {
                connectionFactory = 
                    SampleUtilities.getConnectionFactory();
                connection = 
                    connectionFactory.createConnection();
                session = connection.createSession(false, 
                    Session.AUTO_ACKNOWLEDGE);
                System.out.println("PUBLISHER: Created " +
                    "auto-acknowledge session");
                topic = SampleUtilities.getTopic(topicName, 
                    session);
            } catch (Exception e) {
                System.err.println("Connection problem: " + 
                    e.toString());
                if (connection != null) {
                    try {
                        connection.close();
                    } catch (JMSException ee) {}
                }
                System.exit(1);
            }

            /*
             * After synchronizing with subscriber, create 
             *   publisher.
             * Send 3 messages, varying text slightly.
             * Send end-of-messages message.
             */
            try {
                /*
                 * Synchronize with subscriber.  Wait for message
                 * indicating that subscriber is ready to receive
                 * messages.
                 */
                try {
                    SampleUtilities.receiveSynchronizeMessages("PUBLISHER: ",
                        CONTROL_QUEUE, 1);
                } catch (Exception e) {
                    System.err.println("Queue probably " +
                        "missing: " + e.toString());
                    if (connection != null) {
                        try {
                            connection.close();
                        } catch (JMSException ee) {}
                    }
                    System.exit(1);
                }

                publisher = session.createProducer(topic);
                message = session.createTextMessage();
                for (int i = 0; i < NUMMSGS; i++) {
                    message.setText(MSG_TEXT + " " + (i + 1));
                    System.out.println("PUBLISHER: Publishing " +
                        "message: " + message.getText());
                    publisher.send(message);
                }
                
                /*
                 * Send a non-text control message indicating 
                 * end of messages. 
                 */
                publisher.send(session.createMessage());
            } catch (JMSException e) {
                System.err.println("Exception occurred: " + 
                    e.toString());
            } finally {
                if (connection != null) {
                    try {
                        connection.close();
                    } catch (JMSException e) {}
                }
            }
        }
    }
    
    /**
     * Instantiates the sender, receiver, subscriber, and
     * publisher classes and starts their threads.
     * Calls the join method to wait for the threads to die.
     */
    public void run_threads() {
        SynchSender        synchSender = new SynchSender();
        SynchReceiver      synchReceiver = new SynchReceiver();
        AsynchSubscriber   asynchSubscriber = 
                                        new AsynchSubscriber();
        MultiplePublisher  multiplePublisher = 
                                       new MultiplePublisher();
        
        synchSender.start();
        synchReceiver.start();
        try {
            synchSender.join();
            synchReceiver.join();
        } catch (InterruptedException e) {}

        asynchSubscriber.start();
        multiplePublisher.start();
        try {
            asynchSubscriber.join();
            multiplePublisher.join();
        } catch (InterruptedException e) {}
    }

    /**
     * Reads the queue and topic names from the command line,
     * then calls the run_threads method to execute the program
     * threads.
     *
     * @param args    the topic used by the example
     */
    public static void main(String[] args) {
        AckEquivExample  aee = new AckEquivExample();
        
        if (args.length != 0) {
            System.out.println("Program takes no arguments.");
            System.exit(1);
        }
        System.out.println("Queue name is " + aee.CONTROL_QUEUE);
        System.out.println("Queue name is " + aee.queueName);
        System.out.println("Topic name is " + aee.topicName);
        System.out.println("Connection factory name is " + 
            aee.conFacName);

        aee.run_threads();
        System.exit(0);
    }
}