JMS Tutorial : Topic Subscriber Client

This is in continuation of my tutorial on JMS. The below client uses topic to communicate with the ActiveMQ.

The jndi.properties

# START SNIPPET: jndi 

java.naming.factory.initial = org.apache.activemq.jndi.ActiveMQInitialContextFactory 

# use the following property to configure the default connector 
java.naming.provider.url = tcp://localhost:61616 

# use the following property to specify the JNDI name the connection factory 
# should appear as. 
#connectionFactoryNames = connectionFactory, queueConnectionFactory, topicConnectionFactry 
connectionFactoryNames = connectionFactory, queueConnectionFactory, topicConnectionFactry 

# register some queues in JNDI using the form 
# queue.[jndiName] = [physicalName] 

# register some topics in JNDI using the form 
# topic.[jndiName] = [physicalName] 
#topic.MyTopic = example.MyTopic 
topic.sample.data = sample.data 

# END SNIPPET: jndi 

/** 
* @author shreyas.purohit 
* 
*/ 
public class SampleJMSConsumer implements Runnable { 

    public void run() { 
        Context jndiContext = null; 
        TopicConnectionFactory connectionFactory = null; 
        TopicConnection connection = null; 
        TopicSession session = null; 
        TopicSubscriber consumer = null; 
        Topic destination = null; 
        String sourceName = null; 
        final int numMsgs; 
        sourceName = "sample.data"; 

        /* 
         * Create a JNDI API InitialContext object 
         */ 
        try { 
            jndiContext = new InitialContext(); 
        } catch (NamingException e) { 
            e.printStackTrace(); 
            System.exit(1); 
        } 

        /* 
         * Look up connection factory and destination. 
         */ 
        try { 
            connectionFactory = (TopicConnectionFactory) jndiContext 
                    .lookup("topicConnectionFactry"); 
            destination = (Topic)jndiContext.lookup(sourceName); 
        } catch (NamingException e) { 
            e.printStackTrace(); 
            System.exit(1); 
        } 

        try { 
            connection = connectionFactory.createTopicConnection(); 
            session = connection.createTopicSession(false, TopicSession.AUTO_ACKNOWLEDGE); 
            consumer = session.createSubscriber(destination); 
            connection.start(); 
            try { 
                Thread.sleep(2000); 
            } catch (InterruptedException e) { 
                // TODO Auto-generated catch block 
                e.printStackTrace(); 
            } 
            MessageListener listener = new MyTopicMessageListener(); 
            consumer.setMessageListener(listener); 
            // Let the thread run for some time so that the Consumer has 
            // suffcient time to consume the message 
            try { 
                Thread.sleep(50000); 
            } catch (InterruptedException e) { 
                // TODO Auto-generated catch block 
                e.printStackTrace(); 
            } 
        } catch (JMSException e) { 
            e.printStackTrace(); 
        } finally { 
            if (connection != null) { 
                try { 
                    connection.close(); 
                } catch (JMSException e) { 
                } 
            } 
        } 
    } 

} 

The message listener:

/** 
* @author shreyas.purohit 
* 
*/ 
public class MyTopicMessageListener implements MessageListener { 

    /* (non-Javadoc) 
     * @see javax.jms.MessageListener#onMessage(javax.jms.Message) 
     */ 
    public void onMessage(Message arg0) { 
        if(arg0 instanceof ObjectMessage){ 
            try { 
            //Print it out 
            System.out.println("Recieved message in listener: " + ((ObjectMessage)arg0).getObject()); 
            System.out.println("Co-Rel Id: " + ((ObjectMessage)arg0).getJMSCorrelationID()); 
            }catch(Exception e){ 
                e.printStackTrace(); 
                System.exit(1); 
            } 
        }else{ 
            System.out.println("~~~~Error in format~~~"); 
        } 
    } 

} 

The JMS Application:

/** 
* @author shreyas.purohit 
* 
*/ 
public class JMSApp { 

    /** 
     * @param args 
     */ 
    public static void main(String[] args) { 
        runInNewthread(new SampleJMSConsumer()); 
    } 
    public static void runInNewthread(Runnable runnable) { 
        Thread brokerThread = new Thread(runnable); 
        brokerThread.setDaemon(false); 
        brokerThread.start(); 
    } 
}