1.引入spring cloud, spring cloud alibaba, spring boot依赖

            <!-- SpringCloud 微服务 -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>2020.0.1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <!-- SpringCloud Alibaba 微服务 -->
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>2021.1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <!-- SpringBoot 依赖配置 -->
            <!--<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.4.2</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>-->

2.引入spring cloud stream rabbit依赖

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

3. 配置

spring:
      cloud:
        stream:
          binders:
            default-rabbit:
              type: rabbit
              environment:
                spring:
                    rabbitmq:
                      host: ${RABBITMQ_HOST:xx}
                      port: ${RABBITMQ_PORT:5672}
                      username: xx
                      password: xx
          bindings:
            #MQ生产者
            test-out-0:
              destination: test-topic
              content-type: application/json
              binder: default-rabbit
            #MQ消费者
            test1-in-0:
              destination: test-topic
              group: test1-group
              content-type: application/json
              binder: default-rabbit
            #MQ消费者
            test2-in-0:
              destination: test-topic
              group: test2-group
              content-type: application/json
              binder: default-rabbit
          rabbit:
            bindings:
              test-out-0:
                producer:
                  routingKeyExpression: headers.type
                  exchange-type: direct
              test1-in-0:
                consumer:
                  bindingRoutingKey: k1
                  exchange-type: direct
                  acknowledge-mode: AUTO
              test2-in-0:
                consumer:
                  bindingRoutingKey: k2
                  exchange-type: direct
                  acknowledge-mode: AUTO
          #消费者方法名
          function:
            definition: test1;test2;

 4 生产者代码

 @Autowired
 private StreamBridge streamBridge;

    @ApiOperation("动态解析并发送消息到指定名称的通道")
    @PostMapping("test/send/{destination}/{routingKey}")
    @ResponseStatus(HttpStatus.ACCEPTED)
    public void send(@PathVariable String destination, @PathVariable String routingKey){
        Map<String,String> payload = new HashMap<>();
        payload.put("key1", "value1");
        payload.put("key2", "value2");
        Message<Map<String, String>> message = MessageBuilder
                .withPayload(payload)
                .setHeader("type", routingKey)
                .build();

        streamBridge.send(destination, message);
    }

// 请求 ： http://localhost/test/send/test-out-0/k2

5 消费者

 @Bean
    public Consumer test1() {
        return request -> {
            log.info("test1 MQ消费  req:{}", request);
        };
    }

    @Bean
    public Consumer test2() {
        return request -> {
            log.info("test2 MQ消费  req:{}", request);
        };
    }

6 源码分析

生产者发送源码分析：

    org.springframework.cloud.stream.function.StreamBridge#send
        SubscribableChannel messageChannel = org.springframework.cloud.stream.function.StreamBridge#resolveDestination  封装channel
            SubscribableChannel messageChannel = new DirectWithAttributesChannel();
            Binding<T> binding = org.springframework.cloud.stream.binding.BindingService#bindProducer
                org.springframework.cloud.stream.binding.BindingService#getBinder
                    org.springframework.cloud.stream.binder.DefaultBinderFactory#getBinder
                    org.springframework.cloud.stream.binder.DefaultBinderFactory#doGetBinder
                    org.springframework.cloud.stream.binder.DefaultBinderFactory#getBinderInstance 
                    
                    1.得到RabbitMessageChannelBinder,启动时注入的org.springframework.cloud.stream.binder.rabbit.config.RabbitMessageChannelBinderConfiguration
                    2.得到DefaultBinderFactory, 启动时注入的org.springframework.cloud.stream.config.BindingServiceConfiguration
            org.springframework.cloud.stream.binding.BindingService#doBindProducer
                org.springframework.cloud.stream.binder.AbstractMessageChannelBinder#doBindProducer
                org.springframework.cloud.stream.binder.AbstractMessageChannelBinder#createProducerMessageHandler
                    org.springframework.cloud.stream.binder.rabbit.RabbitMessageChannelBinder#createProducerMessageHandler
                        MessageHandler endpoint = new AmqpOutboundEndpoint()