springboot 配置RabbitMQ 重试机制

springboot集成rabbitMQ中可以直接在配置文件中启用重试机制，被配置重试相关参数，当消费者在处理消息时如果发生异常则该条消息不会被移出消息队列。只有当正常处理后才会将消息移除队列。

生产者

导入依赖

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.sunyuqi</groupId>
    <artifactId>com.sunyuqi</artifactId>
    <version>1.0-SNAPSHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.1.RELEASE</version>
    </parent>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

配置文件

#RabbitMQ 服务器配置
spring.rabbitmq.host=192.168.130.128
spring.rabbitmq.username=admin
spring.rabbitmq.password=admin

#设置交换器名称
mq.config.exchange=direct_exchange
#设置队列的路由键
mq.config.queue.routing.key=test_key

生产者对象

package com.sunyuqi.routing;

import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class ProducerApp {
    
    
    @Autowired
    private RabbitTemplate rabbitTemplate;

    //exChange 交换机
    @Value("${mq.config.exchange}")
    private String exChange;

    //routingkey 路由键
    @Value("${mq.config.queue.routing.key}")
    private String routingKey;
    /**
     * 发送消息的方法
     * @param msg
     */
    public void send(String msg){
    
    
        //向消息队列发送消息
        //参数1：交换器名称
        //参数2：路由键
        //参数3：消息
       this.rabbitTemplate.convertAndSend(exChange,routingKey,msg);
    }
}

引导类

package com.sunyuqi;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringbootdemoApplication {
    
    

	public static void main(String[] args) {
    
    
		SpringApplication.run(SpringbootdemoApplication.class, args);
	}

}

测试类

package sunyuqi;

import com.sunyuqi.SpringbootdemoApplication;
import com.sunyuqi.routing.ProducerApp;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = SpringbootdemoApplication.class)
public class QueueTest {
    
    

    @Autowired
    private ProducerApp producerApp;

    @Test
    public void test() throws InterruptedException {
    
    

        producerApp.send("hello test");
    }
}

运行测试类，想消费队列中发送一条消息
可以在队列中看到有一条消息就绪（此时没有消费者消费）

消费者

配置文件

#RabbitMQ 服务器配置
spring.rabbitmq.host=192.168.130.128
spring.rabbitmq.username=admin
spring.rabbitmq.password=admin

# 设置消息监听器类型
spring.rabbitmq.listener.type=direct
#开启消费者(程序出现异常的情况下会进行重试，捕获异常重试将不生效)
spring.rabbitmq.listener.simple.retry.enabled=true
#最大重试次数
spring.rabbitmq.listener.simple.retry.max-attempts=4
#重试次数超过上面的设置之后是否丢弃（false不丢弃时需要写相应代码将该消息加入死信队列）
spring.rabbitmq.listener.simple.default-requeue-rejected=true

#设置交换器名称
mq.config.exchange=direct_exchange
#设置队列的路由键
mq.config.queue.routing.key=test_key
#设置队列名称
mq.config.queue=test_queue

消费者对象

package sunyuqi.routing;

import org.springframework.amqp.core.ExchangeTypes;
import org.springframework.amqp.rabbit.annotation.*;
import org.springframework.messaging.handler.annotation.Payload;
import org.springframework.stereotype.Component;

@Component
@RabbitListener(
        bindings = @QueueBinding(
        		// 配置队列名称，并将其持久化
                value = @Queue(value = "${mq.config.queue}",autoDelete = "false"),
                // 配置路由模式交换机名称，并将其持久化
                exchange = @Exchange(value = "${mq.config.exchange}", type = ExchangeTypes.DIRECT,autoDelete = "false"),
                // 路由key
                key = "${mq.config.queue.routing.key}"
        )
)
public class ConsumerApp {
    
    
    /**
     * 接收消息的方法，采用消息队列监听机制
     * @param msg
     */
    int flag=0;
    @RabbitListener("${mq.config.queue}")
    @RabbitHandler
    public void process(@Payload String msg){
    
    
    	flag++;
        int a = 1/0;
    }
}

我们在接受到消息时手动抛出一个异常，通过flag记录重试次数

引导类

package sunyuqi;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringbootdemoApplication {
    
    

	public static void main(String[] args) {
    
    
		SpringApplication.run(SpringbootdemoApplication.class, args);
	}
}

此时消息队列中有一条消息就绪
在消费者内中打一个断点

调试引导类

flag最终值为4
这是由于我们设置的重试次数为4。
重试次数超过4后消息被丢弃。