Spring Cloud Stream使用

Spring Cloud Stream对Spring Cloud体系中的Mq进⾏了很好的上层抽象，可以让我们与具体消息中间件解耦合，屏蔽掉了底层具体MQ消息中间件的细节差异，就像Hibernate屏蔽掉了具体数据库（Mysql/Oracle⼀样）。如此⼀来，我们学习、开发、维护MQ都会变得轻松。⽬前Spring Cloud Stream原生⽀持RabbitMQ和Kafka，阿里在这个基础上提供了RocketMQ的支持

简单使用Spring Cloud Stream 构建基于RocketMQ的生产者和消费者

生产者

pom文件中加入依赖

   <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-stream-rocketmq</artifactId>
            <version>2.1.0.RELEASE</version>
        </dependency>

    </dependencies>

配置文件中增加关于Spring Cloud Stream binder和bindings的配置

spring:
  application:
    name: zhao-cloud-stream-producer
  cloud:
    stream:
      rocketmq:
        binder:
          name-server: 127.0.0.1:9876
        bindings:
          output:
            producer:
              group: test
              sync: true
      bindings:
        output:
          destination: stream-test-topic
          content-type: text/plain # 内容格式。这里使用 JSON

其中destination代表生产的数据发送到的topic
然后定义一个channel用于数据发送

import org.springframework.cloud.stream.annotation.Output;
import org.springframework.messaging.MessageChannel;

public interface TestChannel {
    @Output("output")
    MessageChannel output();
}

最后构造数据发送的接口

@Controller
public class SendMessageController {
    @Resource
    private TestChannel testChannel;

    @ResponseBody
    @RequestMapping(value = "send", method = RequestMethod.GET)
    public String sendMessage() {
        String messageId = UUID.randomUUID().toString();
        Message<String> message = MessageBuilder
                .withPayload("this is a test:" + messageId)
                .setHeader(MessageConst.PROPERTY_TAGS, "test")
                .build();
        try {
            testChannel.output().send(message);
            return messageId + "发送成功";
        } catch (Exception e) {
            return messageId + "发送失败，原因：" + e.getMessage();
        }
    }
}

消费者

消费者的pom引入与生产者相同，在此不再赘述，配置时需要将stream的output修改为input并修改对应属性

spring:
  application:
    name: zhao-cloud-stream-consumer
  cloud:
    stream:
      rocketmq:
        binder:
          name-server: 127.0.0.1:9876
        bindings:
          input:
            consumer:
              tags: test
      bindings:
        input:
          destination: stream-test-topic
          content-type: text/plain # 内容格式。这里使用 JSON
          group: test

另外关于channel的构造也要做同样的修改

import org.springframework.cloud.stream.annotation.Input;
import org.springframework.messaging.SubscribableChannel;

public interface TestChannel {
    @Input("input")
    SubscribableChannel input();
}

最后我在启动类中对收到的消息进行了监听

    @StreamListener("input")
    public void receiveInput(@Payload Message message) throws ValidationException {
        System.out.println("input1 receive: " + message.getPayload() + ", foo header: " + message.getHeaders().get("foo"));
    }

测试结果

Stream其他特性

消息发送失败的处理

消息发送失败后悔发送到默认的一个“topic.errors"的channel中(topic是配置的destination)。要配置消息发送失败的处理，需要将错误消息的channel打开
消费者配置如下

spring:
  application:
    name: zhao-cloud-stream-producer
  cloud:
    stream:
      rocketmq:
        binder:
          name-server: 127.0.0.1:9876
        bindings:
          output:
            producer:
              group: test
              sync: true
      bindings:
        output:
          destination: stream-test-topic
          content-type: text/plain # 内容格式。这里使用 JSON
          producer:
            errorChannelEnabled: true

在启动类中配置错误消息的Channel信息

    @Bean("stream-test-topic.errors")
    MessageChannel testoutPutErrorChannel(){
        return new PublishSubscribeChannel();
    }

新建异常处理service

import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.messaging.Message;
import org.springframework.stereotype.Service;

@Service
public class ErrorProducerService {

    @ServiceActivator(inputChannel = "stream-test-topic.errors")
    public void receiveProducerError(Message message){
        System.out.println("receive error msg :"+message);
    }
}

当发生异常时，由于测试类中已经将异常捕获，处理发送异常主要是在这里进行。模拟，应用与rocketMq断开的场景。可见

消费者错误处理

首先增加配置为

spring:
  application:
    name: zhao-cloud-stream-producer
  cloud:
    stream:
      rocketmq:
        binder:
          name-server: 127.0.0.1:9876
        bindings:
          output:
            producer:
              group: test
              sync: true
      bindings:
        output:
          destination: stream-test-topic
          content-type: text/plain # 内容格式。这里使用 JSON
          producer:
            errorChannelEnabled: true

增加相应的模拟异常的操作

    @StreamListener("input")
    public void receiveInput(@Payload Message message) throws ValidationException {
        //System.out.println("input1 receive: " + message.getPayload() + ", foo header: " + message.getHeaders().get("foo"));
        throw new RuntimeException("oops");
    }
    @ServiceActivator(inputChannel = "stream-test-topic.test.errors")
    public void receiveConsumeError(Message message){
        System.out.println("receive error msg"+message.getPayload());
    }

代码地址https://github.com/zhendiao/deme-code/tree/main/zp

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