ActiveMQ — Getting Started with SpringBoot.

Photo by Thanh Mai Nguyen on Unsplash

In this post, we will attempt to set up a Standalone ActiveMQ Broker/Server instead of the embedded SpringBoot ActiveMQ broker. And establish a Message Producer to the Queue, and the Message consumer.

Standalone ActiveMQ:

1. Download ActiveMQ binary from here.
2. Unzip your bundle, and Open Terminal.
3. Set the Terminal path to ActiveMQ -> bin
4. Write command ./activemq start

5. Open http://localhost:8161/admin/ to confirm the ActiveMQ running.

Configure Message Producer:

We will use Java SpringBoot framework, with activemq starter dependency.

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-activemq</artifactId>
</dependency>

ActiveMQ Producer Config:

@Configuration
public class ActiveMQConfig {

    @Value("${active-mq.broker-url}")
    private String brokerUrl;

    @Bean
    public ConnectionFactory connectionFactory(){
        ActiveMQConnectionFactory activeMQConnectionFactory  = new ActiveMQConnectionFactory();
        activeMQConnectionFactory.setBrokerURL(brokerUrl);
        return  activeMQConnectionFactory;
    }

    @Bean
    public JmsTemplate jmsTemplate(){
        JmsTemplate jmsTemplate = new JmsTemplate();
        jmsTemplate.setConnectionFactory(connectionFactory());
        jmsTemplate.setPubSubDomain(true);  // enable for Pub Sub to topic. Not Required for Queue.
        return jmsTemplate;
    }
}

ActiveMQConnectionFactory will establish connection with our ActiveMQ broker, this can be used for both Queue Connection and Topic Connection. As this implements javax.jms.ConnectionFactory, QueueConnectionFactory, TopicConnectionFactory.

JmsTemplate will be used for sending messages to the Topic/Queue. JmsTemplate.send() can be used for sending text messages. For sending custom messages we can make use of JmsTemplate.convertAndSend().

Adding JmsProducer to send our message.

@Component
@Slf4j
public class JmsProducer {

    @Autowired
    JmsTemplate jmsTemplate;

    @Value("${active-mq.topic}")
    private String topic;

    public void sendMessage(Employee message){
        try{
            log.info("Attempting Send message to Topic: "+ topic);
            jmsTemplate.convertAndSend(topic, message);
        } catch(Exception e){
           log.error("Recieved Exception during send Message: ", e);
        }
    }
}

Now we will expose an api to produce message:

@RestController
@Slf4j
public class ProduceMessageController {

    @Autowired
    JmsProducer jmsProducer;

    @PostMapping(value="/api/employee")
    public Employee sendMessage(@RequestBody Employee employee){
        jmsProducer.sendMessage(employee);
        return employee;
    }
}

This should successfully publish our messages to the ActiveMQ Topic.

Configure Message Consumer:

We will create Bean of DefaultJmsListenerContainerFactory, where we use the ActiveMQConnectionFactory.

@Bean
public ConnectionFactory connectionFactory(){
    ActiveMQConnectionFactory activeMQConnectionFactory  = new ActiveMQConnectionFactory();
    activeMQConnectionFactory.setBrokerURL(brokerUrl);
    activeMQConnectionFactory.setTrustedPackages(Arrays.asList("com.mailshine.springbootstandaloneactivemq"));
    return  activeMQConnectionFactory;
}
@Bean
public DefaultJmsListenerContainerFactory jmsListenerContainerFactory(){
    DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory();
    factory.setConnectionFactory(connectionFactory());
    factory.setPubSubDomain(true);
    return factory;
}

Now will add the Listener:

@Component
@Slf4j
public class JmsConsumer implements MessageListener {


    @Override
    @JmsListener(destination = "${active-mq.topic}")
    public void onMessage(Message message) {
        try{
            ObjectMessage objectMessage = (ObjectMessage)message;
            Employee employee = (Employee)objectMessage.getObject();
            //do additional processing
           log.info("Received Message: "+ employee.toString());
        } catch(Exception e) {
          log.error("Received Exception : "+ e);
        }

    }
}

Start the Spring Boot App.

Attempting: curl -X POST “http://localhost:8080/api/employee" -H “accept: */*” -H “Content-Type: application/json” -d “{ \”employeeFirstName\”: \”shine\”, \”employeeFullName\”: \”shine m test\”, \”employeeId\”: \”129\”, \”employeeLastName\”: \”test\”, \”employeeMiddleName\”: \”m\”}”

Or Post call to http://localhost:8080/api/employee

The message should be published successfully to the ActiveMQ Topic.

The message should also be successfully subscribed by the consumer from the Topic.

shinemon/demo-spring-boot

Working example is available in GitHub.

Hope this helps to successfully setup ActiveMQ, and establish Producer / Consumer connection to the ActiveMQ server.

🙏