Not able to publish a message onto RabbitMQ using header exchange with Spring Boot

Question

I have a very basic Spring Boot application that is publishing two messages to RabbitMQ using headers exchange. Both the exchange and queue is getting created but the message is not reaching to the queue. I do not see any exception either.

I googled around but could not find any examples related to this.

BasicApplication.java

@SpringBootApplication
public class BasicApplication {

    public static final String QUEUE_NAME = "helloworld.header.red.q";
    public static final String EXCHANGE_NAME = "helloworld.header.x";

    //here the message ==> xchange ==> queue1, queue2
    @Bean
    public List<Object> headerBindings() {
        Queue headerRedQueue = new Queue(QUEUE_NAME, false);
        HeadersExchange headersExchange = new HeadersExchange(EXCHANGE_NAME);
        return Arrays.asList(headerRedQueue, headersExchange,
                bind(headerRedQueue).to(headersExchange).where("color").matches("red"));
    }

    public static void main(String[] args) {
        SpringApplication.run(BasicApplication.class, args).close();
    }

}

Producer.java

@Component
public class Producer implements CommandLineRunner {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    @Override
    public void run(String... args) throws Exception {
        MessageProperties messageProperties = new MessageProperties();

        //send a message with "color: red" header in the queue, this will show up in the queue
        messageProperties.setHeader("color", "red");
        //MOST LIKELY THE PROBLEM IS HERE
        //BELOW MESSAGE IS NOT LINKED TO ABOVE messageProperties OBJECT
        this.rabbitTemplate.convertAndSend(EXCHANGE_NAME, "", "Hello World !");

        //send another message with "color: gold" header in the queue, this will NOT show up in the queue
        messageProperties.setHeader("color", "gold");
        this.rabbitTemplate.convertAndSend(EXCHANGE_NAME, "", "Hello World !");
    }

}

Answer 1

You're correct in that the MessageProperties you're creating aren't being used.

Trying building a Message that leverages MessageProperties with the help of a MessageConverter.

Example:

MessageProperties messageProperties = new MessageProperties();
messageProperties.setHeader("color", "red");
MessageConverter messageConverter = new SimpleMessageConverter();
Message message = messageConverter.toMessage("Hello World !", messageProperties);
rabbitTemplate.send("helloworld.header.x", "", message);