EN
Spring Boot 2 - broadcast messages to each application instance using RabbitMQ
3 points
In this article, we would like to show you how to create Spring Boot 2 application that broadcasts messages to each application instance that uses RabbitMQ.
In this section, we can find a simplified solution that realizes broadcasting.
Hint: the article extends project in this article.
ProducerConfig.java file:
xxxxxxxxxx1
package com.example.demo;2
3
import org.springframework.amqp.core.FanoutExchange;4
import org.springframework.context.annotation.Bean;5
import org.springframework.context.annotation.Configuration;6
7
8
public class ProducerConfig {9
10
11
public FanoutExchange broadcastExchange() {12
return new FanoutExchange("my-exchange");13
}14
}
ProducerController.java file:
xxxxxxxxxx1
package com.example.demo;2
3
import org.springframework.beans.factory.annotation.Autowired;4
import org.springframework.stereotype.Controller;5
import org.springframework.web.bind.annotation.RequestMapping;6
import org.springframework.web.bind.annotation.ResponseBody;7
8
9
public class ProducerController {10
11
12
private ProducerService producerService;13
14
("/test")15
16
public void test() {17
this.producerService.broadcastMessage("Testing message...");18
}19
}
ProducerService.java file:
xxxxxxxxxx1
package com.example.demo;2
3
import org.springframework.amqp.rabbit.core.RabbitTemplate;4
import org.springframework.beans.factory.annotation.Autowired;5
import org.springframework.stereotype.Service;6
7
8
public class ProducerService {9
10
11
private RabbitTemplate template;12
13
public void broadcastMessage(String message) {14
this.template.convertAndSend("my-exchange", "", message); // broadcasts string message to each my-queue-* via my-exchange15
}16
}
ConsumerConfig.java file:
xxxxxxxxxx1
package com.example.demo;2
3
import org.springframework.amqp.core.Binding;4
import org.springframework.amqp.core.BindingBuilder;5
import org.springframework.amqp.core.FanoutExchange;6
import org.springframework.amqp.core.Queue;7
import org.springframework.amqp.rabbit.annotation.EnableRabbit;8
import org.springframework.amqp.rabbit.connection.ConnectionFactory;9
import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;10
import org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter;11
import org.springframework.context.annotation.Bean;12
import org.springframework.context.annotation.Configuration;13
14
import java.util.UUID;15
16
17
18
public class ConsumerConfig {19
20
21
public String instanceId() {22
return "id-" + UUID.randomUUID();23
}24
25
26
public FanoutExchange broadcastExchange() {27
return new FanoutExchange("my-exchange");28
}29
30
31
public Queue instanceQueue(String instanceId) {32
return new Queue("my-queue-" + instanceId, true);33
}34
35
36
public Binding instanceBinding(Queue instanceQueue, FanoutExchange broadcastExchange) {37
return BindingBuilder.bind(instanceQueue).to(broadcastExchange);38
}39
40
41
public SimpleMessageListenerContainer container(String instanceId, ConnectionFactory connectionFactory, MessageListenerAdapter listenerAdapter) {42
SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();43
container.setConnectionFactory(connectionFactory);44
container.setQueueNames("my-queue-" + instanceId);45
container.setMessageListener(listenerAdapter);46
return container;47
}48
}
ConsumerService.java file:
xxxxxxxxxx1
package com.example.demo;2
3
import org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter;4
import org.springframework.context.annotation.Bean;5
import org.springframework.stereotype.Service;6
7
8
public class ConsumerService {9
10
11
public MessageListenerAdapter listenerAdapter(ConsumerService consumerService) {12
return new MessageListenerAdapter(consumerService, "handleMessage");13
}14
15
public void handleMessage(String message) {16
System.out.println("Message: " + message);17
}18
}
