等性1.1、概念1.2、产生业务场景

2、全局唯一IDRedis解决消息幂等性问题2.1、application.yml配置文件2.2、生产者发送消息2.3、消费者接收消息2.4、pom.xml引入依赖2.5、RabbitConfig配置类2.6、启动类2.7、订单对象2.8、测试

https://blog.csdn.net/weixin_63267801/article/details/134211065

1.1、概念

对于一个资源不管你请求一次还是请求多次对该资源本身造成的影响应该是相同的不能因为重复的请求而对该资源重复造成影响。

1.2、产生业务场景

同一个消息第一次接收正常处理业务如果该消息第二次再接收那就不能再处理业务否则就处理重复了。

配置rabbitmq和redis

rabbit_13_idempotent01_redisrabbitmq:host:

5672username:

truelistener:simple:acknowledge-mode:

manual

exchange.idempotent.01queueName:

使用com.fasterxml.jackson.databind.ObjectMapper对象进行数据序列化与反序列化

package

com.fasterxml.jackson.core.JsonProcessingException;

import

com.fasterxml.jackson.databind.ObjectMapper;

import

org.springframework.amqp.core.Message;

import

org.springframework.amqp.core.MessageBuilder;

import

org.springframework.amqp.core.MessageDeliveryMode;

import

org.springframework.amqp.core.MessageProperties;

import

org.springframework.amqp.rabbit.core.RabbitTemplate;

import

org.springframework.context.annotation.Bean;

import

org.springframework.stereotype.Service;import

javax.annotation.PostConstruct;

import

rabbitTemplate;//这个对象可以进行序列化和反序列化json格式Resourceprivate

ObjectMapper

objectMapper;//构造方法执行后执行PostConstructpublic

void

init(){//开启生产者的确认模式rabbitTemplate.setConfirmCallback((correlationData,

ack,

{//如果交换机接收消息成功ack返回trueif(!ack){log.error(消息没有到达交换机原因是{},cause);//TODO

void

Orders.builder().orderId(order_100).orderName(手机).money(new

BigDecimal(2345)).orderTime(new

Date()).build();//将对象转换成jsonlog.info(orders1:::::

strOrders1

objectMapper.writeValueAsString(orders1);log.info(strOrders1:::::

messageProperties

MessageProperties();//设置单条消息持久化默认技术持久化的messageProperties.setDeliveryMode(MessageDeliveryMode.PERSISTENT);Message

message

MessageBuilder.withBody(strOrders1.getBytes()).andProperties(messageProperties).build();rabbitTemplate.convertAndSend(exchange.idempotent.01,

info,

Orders.builder().orderId(order_100).orderName(手机).money(new

BigDecimal(2345)).orderTime(new

strOrders2

objectMapper.writeValueAsString(orders2);MessageProperties

messageProperties

MessageProperties();//设置单条消息持久化默认技术持久化的messageProperties.setDeliveryMode(MessageDeliveryMode.PERSISTENT);Message

message

MessageBuilder.withBody(strOrders2.getBytes()).andProperties(messageProperties).build();rabbitTemplate.convertAndSend(exchange.idempotent.01,

info,

message);}log.info(消息发送完毕发送时间是new

Date());}

com.fasterxml.jackson.databind.ObjectMapper;

import

org.springframework.amqp.core.Message;

import

org.springframework.amqp.rabbit.annotation.RabbitListener;

import

org.springframework.data.redis.core.StringRedisTemplate;

import

org.springframework.stereotype.Component;import

import

stringRedisTemplate;RabbitListener(queues

void

message.getMessageProperties().getDeliveryTag();//使用objectMapper把字节数组反序列化成对象Orders

orders

objectMapper.readValue(message.getBody(),

Orders.class);try{log.info(接收到的消息为{},orders.toString());//如果不存在就在redis中存储Boolean

setResult

stringRedisTemplate.opsForValue().setIfAbsent(idempotent:

orders.getOrderId(),

orders.getOrderId());if(setResult){//TODO

向数据插入订单数据log.info(向数据库插入订单);}//手动确认接收消息成功channel.basicAck(deliveryTag,false);}catch

(Exception

{channel.basicNack(deliveryTag,false,true);}

catch

xmlnshttp://maven.apache.org/POM/4.0.0

xmlns:xsihttp://www.w3.org/2001/XMLSchema-instancexsi:schemaLocationhttp://maven.apache.org/POM/4.0.0

http://maven.apache.org/xsd/maven-4.0.0.xsdmodelVersion4.0.0/modelVersiongroupIdcom.power/groupIdartifactIdrabbit_13_idempotent01_redis/artifactIdversion1.0-SNAPSHOT/versionnamerabbit_13_idempotent01_redis/namepropertiesmaven.compiler.source8/maven.compiler.sourcemaven.compiler.target8/maven.compiler.targetproject.build.sourceEncodingUTF-8/project.build.sourceEncoding/propertiesparentgroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-parent/artifactIdversion2.6.13/versionrelativePath//parentdependenciesdependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-web/artifactId/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-test/artifactIdscopetest/scope/dependencydependencygroupIdorg.projectlombok/groupIdartifactIdlombok/artifactIdversion1.18.24/version/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-amqp/artifactId/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-data-redis/artifactId/dependency/dependenciesbuildpluginsplugingroupIdorg.springframework.boot/groupIdartifactIdspring-boot-maven-plugin/artifactId/plugin/plugins/build/project2.5、RabbitConfig配置类

package

org.springframework.amqp.core.*;

import

org.springframework.beans.factory.annotation.Value;

import

org.springframework.context.annotation.Bean;

import

org.springframework.context.annotation.Configuration;Configuration

public

{Value(${my.exchangeName})private

String

exchangeName;Value(${my.queueName})private

String

ExchangeBuilder.directExchange(exchangeName).build();}//创建队列Beanpublic

Queue

QueueBuilder.durable(queueName).build();}Beanpublic

Binding

BindingBuilder.bind(queue).to(directExchange).with(info);}

}2.6、启动类

org.springframework.boot.ApplicationArguments;

import

org.springframework.boot.ApplicationRunner;

import

org.springframework.boot.SpringApplication;

import

org.springframework.boot.autoconfigure.SpringBootApplication;import

javax.annotation.Resource;SpringBootApplication

public

{SpringApplication.run(Application.class);}Overridepublic

void

lombok.NoArgsConstructor;import

import

两笔消息订单ID相同但是消费者只把接收到的一条消息插入了数据库实现了消息幂等性。