21.SpringBoot整合docker

简介

整合RabbitMQ服务器，并且通过它怎么去发送和接收消息。我将构建一个springboot工程，通过RabbitTemplate去通过MessageListenerAdapter去订阅一个POJO类型的消息。

构建

IDEA 新建选择 Messaging RabbitMQ

或者引入依赖

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

配置连接RabbitMQ

spring.rabbitmq.host=192.168.1.107
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest

创建消息接收者

在任何的消息队列程序中，你需要创建一个消息接收者，用于响应发送的消息。

@Component
public class Receiver {
    private CountDownLatch latch = new CountDownLatch(1);
    public void receiveMessage(String message) {
        System.out.println("Received <" + message + ">");
        latch.countDown();
    }
    public CountDownLatch getLatch() {
        return latch;
    }
}

消息接收者是一个简单的POJO类，它定义了一个方法去接收消息，当你注册它去接收消息，你可以给它取任何的名字。其中，它有CountDownLatch这样的一个类，它是用于告诉发送者消息已经收到了，你不需要在应用程序中具体实现它，只需要latch.countDown()就行了。

创建消息监听，并发送一条消息

在spring程序中，RabbitTemplate提供了发送消息和接收消息的所有方法。你只需简单的配置下就行了：

• 需要一个消息监听容器

• 声明一个quene,一个exchange,并且绑定它们

• 一个组件去发送消息

  @SpringBootApplication
  public class SpringbootRabbitmqApplication {
  
    static final String topicExchangeName = "spring-boot-exchange";
  
    static final String queueName = "spring-boot";
  
    @Bean
    Queue queue() {
        return new Queue(queueName, false);
    }
  
    @Bean
    TopicExchange exchange() {
        return new TopicExchange(topicExchangeName);
    }
  
    @Bean
    Binding binding(Queue queue, TopicExchange exchange) {
        return BindingBuilder.bind(queue).to(exchange).with("foo.bar.#");
    }
  
    @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) {
        SpringApplication.run(SpringbootRabbitmqApplication.class, args);
    }
  

}

#### 创建测试方法

@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(SpringbootRabbitmqApplication.queueName, "Hello from RabbitMQ!");
    receiver.getLatch().await(10000, TimeUnit.MILLISECONDS);
    context.close();
}

}

启动服务发现控制台输出，测试成功

Sending message…
Received <Hello from RabbitMQ!>

#### 官网地址

https://spring.io/guides/gs/messaging-rabbitmq/

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