How to read pending messages from an ActiveMQ queue in Spring Boot

Question

I like to read pending (not acknowledged) messages in a ActiveMQ queue using Spring boot. How to do that?

So far I can read a message the moment it is send to the queue:

@JmsListener(destination = "LOCAL.TEST", 
  containerFactory = "myJmsListenerContainerFactory")
public void receiveMessage(final Message jsonMessage) throws JMSException {
    String messageData = null;
    // jsonMessage.acknowledge(); // dont consume message (for testing)
    LOGGER.info("=== Received message {}", jsonMessage);
}

using a standard configuration for the mq-connection:

@Bean
public ActiveMQConnectionFactory getActiveMQConnectionFactory() {
    ActiveMQConnectionFactory activeMQConnectionFactory = new ActiveMQConnectionFactory();
    activeMQConnectionFactory.setBrokerURL(BROKER_URL + ":" + BROKER_PORT);
    return activeMQConnectionFactory;
}

and a standard ListenerContainerFactory:

@Bean
public DefaultJmsListenerContainerFactory myJmsListenerContainerFactory() {
  DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory();
  factory.setConnectionFactory(getActiveMQConnectionFactory());
  factory.setConcurrency("1-1");
  return factory;
}

But this just loggs a message if I manually send one using

@Autowired
private JmsTemplate jmsTemplate;

public void send(String destination, String message) {
    LOGGER.info("sending message='{}' to destination='{}'", message, destination);
    jmsTemplate.convertAndSend(destination, message);
}

with the standard template

@Bean
public JmsTemplate jmsTemplate() {
  JmsTemplate template = new JmsTemplate();
  template.setConnectionFactory(getActiveMQConnectionFactory());
  return template;
}

I cannot read messages sent earlier that are still in the Queue (since I didn't .acknowledge() them)...

Answer 1

JMS supports "browsing" messages which appears to be the functionality you want. You should therefore change your Spring application to use a QueueBrowser instead of actually consuming the messages.