Question

I am trying to run a very basic application to learn Spring JMS + ActiveMQ. I see my Producer creating the message (sysout), but nothing shows up in my Consumer and no exception is thrown. I think I am missing something simple here; would really appreciate any help.

[EDITED, THE FOLLOWING CODE WORKS]

Producer:

@Component
public class JmsMessageProducer
{
    @Autowired
    private JmsTemplate template;

    public void generateMessages() throws JMSException
    {
        template.send(new MessageCreator()
        {
            public Message createMessage(Session session) throws JMSException
            {
                System.out.println("sending..");
                TextMessage message = session.createTextMessage("this is a Producer created message!");
                return message;
            }
        });
    }
}

Consumer:

@Component
public class JmsMessageConsumer implements MessageListener {
    @Override
    public void onMessage(Message message) {
        if (message instanceof TextMessage) {
            TextMessage tm = (TextMessage) message;
            try {
                System.out.println("CONSUMER - received ["+tm.getText()+"]");
            }
            catch (Throwable th) {
                th.printStackTrace();
            }
        }
    }
}

Producer Configuration:

<context:component-scan base-package="mrpomario.springcore.jms"/> <!-- finds the JmsMessageProducer -->

<bean id="connectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
    <property name="brokerURL" value="tcp://localhost:8082"/>
</bean>

<bean id="pomarioQueue" class="org.apache.activemq.command.ActiveMQQueue">
    <constructor-arg value="mrpomario.springcore.jms.queue"/>
</bean>

<bean id="jmsTemplate" class="org.springframework.jms.core.JmsTemplate">
    <property name="connectionFactory" ref="connectionFactory"/>
    <property name="defaultDestination" ref="pomarioQueue"/>
</bean>

Consumer Configuration:

<jms:listener-container>
    <jms:listener ref="jmsMessageConsumer" method="onMessage" destination="mrpomario.springcore.jms.queue"/>
</jms:listener-container>

<bean id="pomarioQueue" class="org.apache.activemq.command.ActiveMQQueue">
    <constructor-arg value="mrpomario.springcore.jms.queue"/>
</bean>

<bean id="connectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
    <property name="brokerURL" value="tcp://localhost:8082"/>
</bean>

<amq:broker id="broker" useJmx="false" persistent="false">
    <amq:transportConnectors>
        <amq:transportConnector uri="tcp://localhost:8082" />
    </amq:transportConnectors>
</amq:broker>

Test Case:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:mrpomario/springcore/jms/jms-config.xml")
public class JmsTest
{
    @Autowired
    JmsMessageProducer jmsMessageProducer;

    @Test
    public void test_Single_Queue_Producer_and_Consumer_Unidirectional() throws JMSException
    {
        try
        {
            jmsMessageProducer.generateMessages();
            assertTrue(true);
        }
        catch (Throwable th)
        {
            System.out.println("\n\nJmsTest: remote invocation failed. Ensure the web server is running.\n\n");
        }
    }
}

I run the producer inside a Java EE container (mvn jetty:run) where a Spring MVC application also runs.

Answer 1

I think you are ending up sending to and consuming from two completely different brokers(and subsequently different queues):

Have your broker defined in only one place, say your producer config:

<amq:broker id="broker" useJmx="false" persistent="false">
    <amq:transportConnectors>
        <amq:transportConnector uri="tcp://localhost:8082" />
        <amq:transportConnector uri="vm://localhost" />
    </amq:transportConnectors>
</amq:broker>

<amq:connectionFactory id="jmsFactory" brokerURL="vm://localhost" />

From your consumer config remove the broker configuration and have only the connectionFactory:
Either (if you are in the same VM):

<amq:connectionFactory id="jmsFactory" brokerURL="vm://localhost" />

Or(If remote):

<amq:connectionFactory id="jmsFactory" brokerURL="tcp://localhost:8082" />