SpringCloud Stream 消息同步和异步

柔光的暖阳◎ 2022-04-04 14:40 606阅读 0赞

1.异步的形式有

通知：单向请求，只管发送不关心结果。

请求/异步响应：一对一的交互。请求的信息不回立马返回，而是过一段时间再返回结果。

消息：利用消息可以实现一对多形态的交互。

2.MQ的应用场景；异步处理、流量削锋、日志处理、应用解耦

3.pom文件引入架包依赖

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

4.配置文件配置rabbitmq参数

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lpeWlqaWFueGlhbg_size_16_color_FFFFFF_t_70][]

5.代码实现

import org.springframework.cloud.stream.annotation.Input;
    import org.springframework.cloud.stream.annotation.Output;
    import org.springframework.messaging.MessageChannel;
    import org.springframework.messaging.SubscribableChannel;
    
    public interface StreamClient {
    
    	@Input("myMessage2")
    	SubscribableChannel input();
    	
    	@Output("myMessage")
    	MessageChannel output();
    	
    }

import org.springframework.cloud.stream.annotation.EnableBinding;
    import org.springframework.cloud.stream.annotation.StreamListener;
    import org.springframework.stereotype.Component;
    
    import lombok.extern.slf4j.Slf4j;
    
    /**
     * 消息接收端
     * @author lf
     *
     */
    @Component
    @EnableBinding(StreamClient.class)
    @Slf4j
    public class StreamReceiver {
    
    	@StreamListener("myMessage")
    	public void process(Object message) {
    		log.info("-------------StreamReceiver-------:{}",message);
    		
    	}
    }

import java.util.Date;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.messaging.support.MessageBuilder;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    /**
     * 消息发送
     * @author lf
     *
     */
    @RestController
    public class SendMessageController {
    
    	@Autowired
    	private StreamClient streamClient;
    	
    	@GetMapping("/sendMessage")
    	public void process() {
    		streamClient.output().send(MessageBuilder.withPayload("now time is "+new Date()).build());
    	}
    	
    }

6.启动项目在rabbitMQ上查看队列是否创建完成

![20181222104730973.png][]

7.如何只让一个实例收到消息

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lpeWlqaWFueGlhbg_size_16_color_FFFFFF_t_70 1][]

![20181222105516704.png][]

8.当传递的不是字符串而是对象是如何在mq对了上直接显示对象内容

![20181222145202508.png][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lpeWlqaWFueGlhbg_size_16_color_FFFFFF_t_70]: /images/20220404/8688f49054c5438295f49b4279765818.png
[20181222104730973.png]: /images/20220404/9de390d616bc4f50abc6b1b280e44f32.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lpeWlqaWFueGlhbg_size_16_color_FFFFFF_t_70 1]: /images/20220404/c25016fed1604539bc15cddd78482491.png
[20181222105516704.png]: /images/20220404/34f9b0bac9424ecba0f68a5075a0e727.png
[20181222145202508.png]: /images/20220404/6487338c63914182bbc08b7f1f1a7577.png