Java EE: Asynchronously receiving messages from a message queue

The JMSConsumer.receiveBody() method has a disadvantage: it blocks execution until a message is received from the queue. We can prevent our JMS consumer code from blocking execution by receiving messages asynchronously via an implementation of the javax.jms.MessageListener interface.

import javax.jms.JMSException;

import javax.jms.Message;

import javax.jms.MessageListener;

import javax.jms.TextMessage;

public class ExampleMessageListener implements MessageListener {

@Override

public void onMessage(Message message) {

   TextMessage textMessage = (TextMessage) message;

   try {

      System.out.print("Received the following message: ");

      System.out.println(textMessage.getText());

      System.out.println();

   } catch (JMSException e) {

     e.printStackTrace();

}

}

}

Our main code can now delegate message retrieval to our custom MessageListener implementation:

jMSConsumer.setMessageListener(new ExampleMessageListener());