How to wait for @JMSListener annotated method to complete in JUnit

Question

So I am trying to get some integration testing of JMS processing, Spring (v4.1.6) based code.

It\'s a very standard Spring setup with @JmsListener annotate

Answer 1

Well, I was hoping I can somehow hook into the Message Driven Pojos lifecycle to do this, but going through other SO questions about async code I came up with a solution based on CountDownLatch

1. The @JMSListener annotaded method should call countDown() on a CountDownLatch after all the work is complete:

   @JmsListener(destination = "dest", containerFactory = "cf")
   public void processMessage(TextMessage message) throws JMSException {
       //do the actual processing
       actualProcessing(message);
       //if there's countDownLatch call the countdown.
       if(countDownLatch != null) {
           countDownLatch.countDown();
       }
   }
   

2. In the testMethod

   @Test
   public void test() throws InterruptedException {
       //initialize the countDownLatch and set in on the processing class
       CountDownLatch countDownLatch = new CountDownLatch(1);
       messageProcessor.setCountDownLatch(countDownLatch);
       //sendthemessage
       sendSomeMessage();
       //wait for the processing method to call countdown()
       countDownLatch.await();
       verify();
   }
   

The drawback of this solution is that you have to actually change your @JMSListener annotated method specifically for the integration test