How can I prevent Spring JmsTemplate unit test from blocking when reading ActiveMQ queue?

Question

How can I prevent Spring JmsTemplate unit test sendAndReceivePerson() from blocking when attempting to read a Person object from ActiveMQ queue person.queue?

The test creates a Person object, sends it to queue person.queue (this should also create the embedded broker that contains the queue), and then attempts to read the object from the same queue.

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {MessagingConfiguration.class})
public class PersonMessengerTest {
    @Autowired
    private PersonMessenger personMessenger;

    @Test
    public void sendAndReceivePerson() {
        final Person person = new Person();
        final UUID id = UUID.randomUUID();
        person.setId(id);
        person.setFirstName("Derek");
        person.setLastName("Mahar");
        personMessenger.sendPersion(person);
        final Person receivedPersion = personMessenger.receivePersion();
        assertEquals(id, receivedPersion.getId());
    }
}

public class PersonMessenger {

    private final JmsOperations jmsOperations;

    public PersonMessenger(JmsOperations jmsOperations) {
        this.jmsOperations = jmsOperations;
    }

    public void sendPersion(final Person person) {
        this.jmsOperations.convertAndSend(person);
    }

    public Person receivePersion() {
        return (Person) this.jmsOperations.receiveAndConvert();
    }
}

@Configuration
@Import({CommonConfiguration.class})
public class MessagingConfiguration {

    public static final String PERSON_QUEUE = "person.queue";

    @Autowired
    private ApplicationEnvironment applicationEnvironment;

    @Bean
    public ConnectionFactory jmsConnectionFactory() {
        final ActiveMQConnectionFactory activeMqConnectionFactory = new ActiveMQConnectionFactory(
                this.applicationEnvironment.getJmsBrokerUrl());
        activeMqConnectionFactory.setTrustAllPackages(true);
        return activeMqConnectionFactory;
    }

    @Bean
    public JmsOperations jmsTemplate(ConnectionFactory connectionFactory) {
        final JmsTemplate jmsTemplate = new JmsTemplate(connectionFactory);
        jmsTemplate.setDefaultDestinationName(PERSON_QUEUE);
        return jmsTemplate;
    }

    @Bean
    public PersonMessenger personMessenger(JmsOperations jmsOperations) {
        return new PersonMessenger(jmsOperations);
    }

    @Bean(name = PERSON_QUEUE)
    public Queue personQueue() {
        return new ActiveMQQueue(PERSON_QUEUE);
    }
}

@Configuration
@PropertySource("classpath:application.properties")
public class CommonConfiguration {

    @Autowired
    private Environment applicationEnvironment;

    @Bean
    public ApplicationEnvironment applicationEnvironment() {
        return new ApplicationEnvironment(this.applicationEnvironment);
    }
}

application.properties:

jms.brokerUrl=vm://test?async=false&broker.persistent=false&broker.useJmx=false

Notice that the test blocks while attempting to read the Person object from the queue:

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running com.opessoftware.example.spring.messenger.PersonMessengerTest
2017-02-15 15:30:33,736|WARN|main|o.a.activemq.broker.BrokerService|49670|
    org.apache.activemq.broker.BrokerService.checkMemorySystemUsageLimits(BrokerService.java:2142)
    Memory Usage for the Broker (1024mb) is more than the maximum available for the JVM: 955 mb - resetting to 70% of maximum available: 668 mb
2017-02-15 15:30:33,993|WARN|main|o.a.activemq.broker.BrokerService|49927|
    org.apache.activemq.broker.BrokerService.checkMemorySystemUsageLimits(BrokerService.java:2142)
    Memory Usage for the Broker (1024mb) is more than the maximum available for the JVM: 955 mb - resetting to 70% of maximum available: 668 mb

Might the receiveAndConvert() call be creating a second embedded broker or might it be reading from a different queue?

Answer 1

A notorious problem when testing with an embedded broker.

The connection is closed between the operations and, without persistence, the data is lost.

Try wrapping the connection factory in a CachingConnectionFactory so the connection stays open (and hence the broker stays up).

You should really use a CachingConnectionFactory with a JmsTemplate anyway, for performance reasons, but it's particularly bad in a unit test.