Spring Cloud Stream简单用法

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

   org.springframework.cloudspring-cloud-starter-netflix-eureka-client com.alibaba.cloudspring-cloud-starter-stream-rocketmq2.1.0.RELEASE

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 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

Spring Cloud Stream简单用法

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

Spring Cloud Stream简单用法

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()); }

Spring Cloud Stream简单用法