Spring Integration, Spring JMS, ActiveMQ and testing Topics

Spring Integration, Spring JMS, ActiveMQ and testing Topics

so everyone knows how to test a JMS Queue in JUnit, ActiveMQ and - to make life easy - Spring JmsTemplate.  but, testing a Topic is a slightly different matter.

first, a topic subscriber has to be 'connected' before you can publish the message.  that's a bit of a challenge to setup.  but, with a little Spring Integration to the rescue we can get a subscriber sorted and sne a message via the JmsTemplate.

another catch comes from ActiveMQ.  to test queues, you can setup the ActiveMQConnectionFactory and you're done.  however, with Topics, you'll need the PooledConnectionFactory as well.

first, a couple dependencies for our pom

   
    org.apache.activemq
    activemq-core
    5.6.0
    test
   
   
    org.apache.activemq
    activemq-pool
    5.6.0
    test
   

then a little Spring Integration to listen to the Topic

(i prefer a queue channel, just to make it easier to get the messages off in testing)
so the next part would be the test class

package de.incompleteco.spring.integration.test;

import static org.junit.Assert.assertNotNull;

import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.Session;
import javax.jms.Topic;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.integration.Message;
import org.springframework.integration.core.PollableChannel;
import org.springframework.jms.core.JmsTemplate;
import org.springframework.jms.core.MessageCreator;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({"classpath:/META-INF/spring/integration-context.xml"})
public class TopicIntegrationTest {

 @Autowired
 private PollableChannel receiveChannel;
 
 @Autowired
 private ConnectionFactory connectionFactory;
 
 @Autowired
 private Topic topic;
 
 private JmsTemplate jmsTemplate;
 
 @Test
 public void test() throws Exception {
  //setup the jmsTemplate and send
  jmsTemplate = new JmsTemplate(connectionFactory);
  jmsTemplate.setDefaultDestination(topic);
  jmsTemplate.setPubSubDomain(true);//it's a topic
  //send
  jmsTemplate.send(new MessageCreator() {

   public javax.jms.Message createMessage(Session session) throws JMSException {
    return session.createTextMessage("hello world");
   } });
  //now grab it off the queue
  Message message = receiveChannel.receive(1000);//let's put a timeout
  //test
  assertNotNull(message);
 }
 
}

and here's the specific apache configuration to support Topics