服务间的消息传递-Stream

1 引言

Stream就是在消息队列的基础上，对其进行封装，让咱们更方便的去操作MQ消息队列。

2 Stream快速入门

启动RabbitMQ
消费者-导入依赖

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-stream-rabbit</artifactId>
</dependency>

消费者-配置文件

spring:
  # 连接RabbitMQ
  rabbitmq:
    host: 192.168.199.109
    port: 5672
    username: test
    password: test
    virtual-host: /test

消费者-监听的队列

public interface StreamClient {
    @Input("myMessage")
    SubscribableChannel input();
}
//-------------------------------------------------
@Component
@EnableBinding(StreamClient.class)
public class StreamReceiver {
    @StreamListener("myMessage")
    public void msg(Object msg){
        System.out.println("接收到消息： " + msg);
    }
}

生产者-导入依赖

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-stream-rabbit</artifactId>
</dependency>

生产者-配置文件

spring:
  # 连接RabbitMQ
  rabbitmq:
    host: 192.168.199.109
    port: 5672
    username: test
    password: test
    virtual-host: /test

生产者-发布消息

public interface StreamClient {
    @Output("myMessage")
    MessageChannel output();
}
//----------------------------------------------  在启动类中添加注解 @EnableBinding(StreamClient.class)
@Autowired
private StreamClient streamClient;
@GetMapping("/send")
public String send(){
    streamClient.output().send(MessageBuilder.withPayload("Hello Stream!!").build());
    return "消息发送成功！！";
}

3 Stream重复消费问题

只需要添加一个配置，指定消费者组

spring:
  cloud:
    stream:
      bindings:
        myMessage:                # 队列名称
          group: customer      # 消费者组

4 Stream的消费者手动ack

编写配置

spring:
  cloud:
    stream:
      # 实现手动ACK
      rabbit:
        bindings:
          myMessage:
            consumer:
              acknowledgeMode: MANUAL

修改消费端方法

@StreamListener("myMessage")
public void msg(Object msg,
                @Header(name = AmqpHeaders.CHANNEL) Channel channel,
                @Header(name = AmqpHeaders.DELIVERY_TAG) Long deliveryTag) throws IOException {
    System.out.println("接收到消息： " + msg);
    channel.basicAck(deliveryTag,false);
}