Spring Boot - RabbitMQ - Request-Reply Pattern

RequestReplyFixed.java

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;
import org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
public class RequestReplyFixed {
	private static final String EX_REPLY_REQUEST = "ex.reply-request";
	private static final String MQ_REQUEST_QUEUE = "mq.request.queue";
	private static final String ROUTING_KEY = "my-key";
	private static final String MQ_REPLY_QUEUE = "mq.reply.queue";

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

	@Bean
	public DirectExchange exchange() {
		return new DirectExchange(EX_REPLY_REQUEST);
	}

	@Bean
	public Binding binding() {
		return BindingBuilder.bind(requestQueue()).to(exchange()).with(ROUTING_KEY);
	}

	@Bean
	public Queue requestQueue() {
		return new Queue(MQ_REQUEST_QUEUE);
	}

	@Bean
	public Queue replyQueue() {
		return new Queue(MQ_REPLY_QUEUE);
	}

	// Client - template sender
	@Bean
	public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory) {
		RabbitTemplate template = new RabbitTemplate(connectionFactory);
		template.setExchange(exchange().getName());
		template.setRoutingKey(ROUTING_KEY);
		template.setReplyAddress(MQ_REPLY_QUEUE);
		return template;
	}

	// Client - listener to reply-response for the client
	@Bean
	public SimpleMessageListenerContainer replyListenerContainer(ConnectionFactory connectionFactory, RabbitTemplate rabbitTemplate) {
		SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
		container.setConnectionFactory(connectionFactory);
		container.setQueues(replyQueue());
		container.setMessageListener(rabbitTemplate);
		return container;
	}

	// Server - request consumer
	@Bean
	public SimpleMessageListenerContainer serviceListenerContainer(ConnectionFactory connectionFactory) {
		SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
		container.setConnectionFactory(connectionFactory);
		container.setQueues(requestQueue());
		container.setMessageListener(new MessageListenerAdapter(new MessageConsumer()));
		return container;
	}
}

@RestController
@RequestMapping("/")
class MessageController {
	private RabbitTemplate rabbitTemplate;

	public MessageController(RabbitTemplate rabbitTemplate) {
		this.rabbitTemplate = rabbitTemplate;
	}

	@GetMapping
	public String home() throws Exception {
		return (String) this.rabbitTemplate.convertSendAndReceive("Hello, world!");
	}
}

class MessageConsumer {
	public String handleMessage(String message) {
		return message.toUpperCase();
	}
}