How to identify the exchange to which the message is routed to in Spring boot rabbitmq?

Question

I am new to Spring AMQP and was just trying to understand RabbitMQ java configuration using annotations. Here the sample code.

Sender code -

@Component
public class Runner implements CommandLineRunner {
    private final RabbitTemplate rabbitTemplate;
    private final Receiver receiver;
    private final ConfigurableApplicationContext context;

    public Runner(Receiver receiver, RabbitTemplate rabbitTemplate,
            ConfigurableApplicationContext context) {
        this.receiver = receiver;
        this.rabbitTemplate = rabbitTemplate;
        this.context = context;
    }

    @Override
    public void run(String... args) throws Exception {
        System.out.println("Sending message...");
        rabbitTemplate.convertAndSend(Application.queueName, "Hello from RabbitMQ!");
        receiver.getLatch().await(10000, TimeUnit.MILLISECONDS);
        context.close();
    }

}

So, here, in convertAndSend(), only the routing key is specified. There is no exchange name given.

The configuration file is as shown below-

@SpringBootApplication
public class Application {

    final static String queueName = "spring-boot";

    final static String HOST = "120.27.114.229";

    final static String USERNAME = "root";

    final static String PASSWORD = "root";

    final static int PORT = 5672;

    @Bean
    Queue queue() {
        return new Queue(queueName, false);
    }

    @Bean
    TopicExchange exchange() {
        return new TopicExchange("spring-boot-exchange");
    }

    @Bean
    Binding binding(Queue queue, TopicExchange exchange) {
        return BindingBuilder.bind(queue).to(exchange).with(queueName);
    }

    @Bean  
    public ConnectionFactory connectionFactory() {  
          CachingConnectionFactory connectionFactory = new CachingConnectionFactory();
          connectionFactory.setHost(HOST);
          connectionFactory.setPort(PORT);
          connectionFactory.setUsername(USERNAME);
          connectionFactory.setPassword(PASSWORD);
          connectionFactory.setVirtualHost("/");
          //����Ҫ����,��Ϣ�Ļص�
          connectionFactory.setPublisherConfirms(true); 
          return connectionFactory;
    } 

    @Bean
    SimpleMessageListenerContainer container(ConnectionFactory connectionFactory,
            MessageListenerAdapter listenerAdapter) {
        SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
        container.setConnectionFactory(connectionFactory);
        container.setQueueNames(queueName);
        container.setMessageListener(listenerAdapter);
        return container;
    }

    @Bean
    MessageListenerAdapter listenerAdapter(Receiver receiver) {
        return new MessageListenerAdapter(receiver, "receiveMessage");
    }

    public static void main(String[] args) throws InterruptedException {
        SpringApplication.run(Application.class, args);
    }

}

Here, the TopicExchange bean is defined and the name is "spring-boot-exchange". So the sender sends message to this exchange?? If there are two exchanges, to which exchange does the sender send messages to ?? Please help.

Gary Russell Gary Russell · Accepted Answer · 2018-03-15T16:17:43

In this case, you are sending to the default exchange "":

rabbitTemplate.convertAndSend(Application.queueName, "Hello from RabbitMQ!");

not your topic exchange.

To send to an explicit exchange, use

rabbitTemplate.convertAndSend("someExchange", "routingKey", "Hello from RabbitMQ!");

EDIT

Or, you can configure the default exchange to be something other than the default exchange. template.setExchange("someExchange").

How to identify the exchange to which the message is routed to in Spring boot rabbitmq?

1 Answers