unable to receive messages from queue in jms

Question

i am a beginner to jms and i am just trying to get a simple web app running that produces and consumes messages. so on my welcome page i have a form with a text box and submit button. on submit the text in the text box is wrapped in a message and sent to the queue on the server via a MessageProducer. from what i understand, this message should remain on the queue until i call the receive method from some MessageConsumer where the consumer is linked to that queue. unfortunately on my second jsp page where i click the "Get Messages" button , the received message turns up null. i am pretty sure they are being sent properly (at least there are no errors saying otherwise) is there a way i could check that though? any ideas on whats going wrong? thanks in advance. heres the producer/consumer code.

public class Producer {           
    private static final String CONNECTION_FACTORY = "connectionFactory";     
    private static final String CONNECTION_QUEUE = "jms/myqueue";    
    private static final String CONNECTION_TOPIC = "jms/mytopic";     

    public Producer(String message) {         
        ConnectionFactory connectionFactory = null;       
        Connection connection = null;         
        //Get the JNDI Context        
        try {        
            Context jndiContext = new InitialContext();      

            //Create the Connection Factory  and Connection     
            connectionFactory = (ConnectionFactory) jndiContext.lookup(Producer.CONNECTION_FACTORY);       
            connection = connectionFactory.createConnection();  

            //Create the session           
            Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);                   

            publishToQueue(jndiContext, session, message);    
            session.commit();
        } catch (NamingException e) {            
        } catch (JMSException e) {    

        }finally{       
           //close connection     
        }   
    }        

    private void publishToQueue(Context jndiContext, Session session, String message) throws NamingException, JMSException{      
        //Create Queue     
        Queue queue = (Queue) jndiContext.lookup(Producer.CONNECTION_QUEUE); 

        //Create Message Producer       
        MessageProducer producer = session.createProducer(queue);     

        //Send TextMessage        
        producer.setDeliveryMode(DeliveryMode.PERSISTENT);
        TextMessage textMessage = session.createTextMessage();    
        textMessage.setText(message);
        producer.send(textMessage);  
        producer.close();

} 
 } 


public class Consumer {           
    private static final String CONNECTION_FACTORY = "connectionFactory";     
    private static final String CONNECTION_QUEUE = "jms/myqueue";    
    private static final String CONNECTION_TOPIC = "jms/mytopic";     

    private Message message;

    public Consumer() {        
        ConnectionFactory connectionFactory = null;       
        Connection connection = null;         
        //Get the JNDI Context        
        try {        
            Context jndiContext = new InitialContext();     

        //Create the Connection Factory       
        connectionFactory = (ConnectionFactory) jndiContext.lookup(Consumer.CONNECTION_FACTORY);       
        connection = connectionFactory.createConnection();  

        //Create the session           
        Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);                   

        //Call methods to retrieve  message      
        message = getFromQueue(jndiContext, session);    
        session.commit();
        if(message!=null){
            System.out.println("Message Received");
        }
    } catch (NamingException e) {            
        // TODO Auto-generated catch block       
        e.printStackTrace();        
    } catch (JMSException e) {    
        // TODO Auto-generated catch block    
        e.printStackTrace();       

    }finally{       
        try {           
            if(connection != null){    
                connection.close();    
            }            
        } catch (JMSException e) {   
            e.printStackTrace();         
        }       
    }   
}        



private Message getFromQueue(Context jndiContext, Session session) throws NamingException, JMSException{      
    //Create new Queue
    Queue queue = (Queue)jndiContext.lookup(Consumer.CONNECTION_QUEUE);  
    //Create Message Consumer       
    MessageConsumer consumer = session.createConsumer(queue); 
    return consumer.receive(10000);    
}

public Message getMessage(){
    return message;
}
}

theGuardian theGuardian · Accepted Answer · 2013-08-01T03:10:29

sorry, found the answer in a another question.. MessageConsumer is not consuming messages .. all i needed was to call connection.start() before the getFromQueue method

 public Consumer() {        
    ConnectionFactory connectionFactory = null;       
    Connection connection = null;         
    //Get the JNDI Context        
    try {        
        Context jndiContext = new InitialContext();     

    //Create the Connection Factory       
    connectionFactory = (ConnectionFactory) jndiContext.lookup(Consumer.CONNECTION_FACTORY);       
    connection = connectionFactory.createConnection();  

    //Create the session           
    Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);                   

    //Call methods to retrieve  message   
     --> connection.start(); <--
    message = getFromQueue(jndiContext, session);    
    session.commit();
    if(message!=null){
        System.out.println("Message Received");
    }

unable to receive messages from queue in jms

1 Answers