RabbitMQ学习08--消息重复消费(SpringBoot方式)

1、添加依赖

修改pom文件，添加spring-data-redis的依赖：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.6</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.yas</groupId>
    <artifactId>RabbitMQBoot</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>RabbitMQBoot</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

2、修改配置文件，application.yml：

spring:
  redis:
    host: ubu
    port: 6379
    password: 123456

3、修改生产者代码：

package com.yas.rabbitmqboot;

import org.junit.jupiter.api.Test;
import org.springframework.amqp.rabbit.connection.CorrelationData;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.io.IOException;
import java.util.UUID;

@SpringBootTest
class RabbitMqBootApplicationTests {
    @Autowired
    RabbitTemplate rabbitTemplate;

    @Test
    void contextLoads() throws IOException {
        CorrelationData messageid = new CorrelationData(UUID.randomUUID().toString());
        rabbitTemplate.convertAndSend("boot-topic-exchange", "slow.red.dog", "慢红狗", messageid);
        System.out.println("消息已生产");
        System.in.read();
    }
}

4、修改消费者代码：

package com.yas.rabbitmqboot.listen;

import com.rabbitmq.client.Channel;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.io.IOException;
import java.util.concurrent.TimeUnit;

@Component
public class Consumer {

    @Autowired
    StringRedisTemplate redisTemplate;

    @RabbitListener(queues = "boot-queue")
    public void getMessage(String msg, Channel channel, Message message) throws IOException {

        //0 获取messageid
        String messageid = message.getMessageProperties().getHeader("spring_returned_message_correlation");

        //1
        if (redisTemplate.opsForValue().setIfAbsent(messageid, "0", 10, TimeUnit.SECONDS)) {
            //执行返回true，表示原来不存在这个值
            System.out.println("接收到消息：" + msg);
            //处理完毕
            redisTemplate.opsForValue().set(messageid, "1");
            //手动ack
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);

        } else {
            //执行返回false，表示原来存在这个值
            if ("1".equalsIgnoreCase(redisTemplate.opsForValue().get(messageid))) {
                //手动ack
                channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
            }else{
                System.out.println("不需要做任何处理");
            }
        }


    }
}