RabbitMQ整合Spring Booot【消费者补偿幂等问题】

如果消费者 运行时候 报错了

package com.toov5.msg.SMS;

import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

@Component
@RabbitListener(queues="fanout_sms_queue")
public class SMSConsumer {

@RabbitHandler
public void process(String mString) {
System.out.println("短信消费者获取生产者消息msg"+mString);
int i = 1/0;
}
}
当生产者投递消息后：

消费者会不停的进行打印:

消息一直没有被消费

原因 Rabbitmq 默认情况下 如果消费者程序出现异常情况 会自动实现补偿机制  也就是 重试机制

@RabbitListener底层使用AOP进行拦截，如果程序没有抛出异常，自动提交事务。 如果Aop使用异常通知 拦截获取异常信息的话 ， 自动实现补偿机制，该消息会一直缓存在Rabbitmq服务器端进行重放，一直重试到不抛出异常为准。

可以修改重试策略

一般来说默认5s重试一次，

消费者配置：

listener:
simple:
retry:
####开启消费者重试
enabled: true
####最大重试次数（默认无数次）
max-attempts: 5
####重试间隔次数
initial-interval: 3000
效果： 充实5次 不行就放弃了

MQ重试机制机制 需要注意的问题

如何合适选择重试机制

情况1:  消费者获取到消息后，调用第三方接口，但接口暂时无法访问，是否需要重试?      需要重试   别人的问题不是我自己的问题

情况2:  消费者获取到消息后，抛出数据转换异常，是否需要重试?                                      不需要重试   充实一亿次也是如此 木有必要  需要发布版本解决

总结：对于情况2，如果消费者代码抛出异常是需要发布新版本才能解决的问题，那么不需要重试，重试也无济于事。应该采用 日志记录+定时任务job健康检查+人工进行补偿

把错误记录在日志里面，通过定时Job去自动的补偿，或通过人工去补偿。

传统的HTTP请求 如果失败了 没法自动重试  当然自己可以写个循环实现

MQ完全自己自带的

情况2的拓展延申：

将之前的案例改为   邮件消费者 调用邮件第三方接口

伪代码：

在consumer 中 调用接口后 判断返回值  由于RabbitMQ 在消费者异常时候 会进行重试机制 进行补偿

所以可以抛出个异常 来实现

Consumer：

String result   =   template.Email();

if(result == null){

throw new Exception("调用第三方邮件服务器接口失败!");

}

producer：

pom:

<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.itmayiedu</groupId>
<artifactId>rabbitmq_producer_springboot</artifactId>
<version>0.0.1-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.0.RELEASE</version>
</parent>
<dependencies>

<!-- springboot-web组件 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- 添加springboot对amqp的支持 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-amqp</artifactId>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency>
<!--fastjson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.49</version>
</dependency>
</dependencies>
</project>
config:

package com.itmayiedu.rabbitmq.config;

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.FanoutExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

//Fanout 类型 发布订阅模式
@Component
public class FanoutConfig {

// 邮件队列
private String FANOUT_EMAIL_QUEUE = "fanout_email_queue";

// 短信队列
private String FANOUT_SMS_QUEUE = "fanout_sms_queue";
// fanout 交换机
private String EXCHANGE_NAME = "fanoutExchange";

// 1.定义邮件队列
@Bean
public Queue fanOutEamilQueue() {
return new Queue(FANOUT_EMAIL_QUEUE);
}

// 2.定义短信队列
@Bean
public Queue fanOutSmsQueue() {
return new Queue(FANOUT_SMS_QUEUE);
}

// 2.定义交换机
@Bean
FanoutExchange fanoutExchange() {
return new FanoutExchange(EXCHANGE_NAME);
}

// 3.队列与交换机绑定邮件队列
@Bean
Binding bindingExchangeEamil(Queue fanOutEamilQueue, FanoutExchange fanoutExchange) {
return BindingBuilder.bind(fanOutEamilQueue).to(fanoutExchange);
}

// 4.队列与交换机绑定短信队列
@Bean
Binding bindingExchangeSms(Queue fanOutSmsQueue, FanoutExchange fanoutExchange) {
return BindingBuilder.bind(fanOutSmsQueue).to(fanoutExchange);
}
}

Producer:

package com.itmayiedu.rabbitmq;

import java.util.UUID;

import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageBuilder;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.alibaba.fastjson.JSONObject;

@Component
public class FanoutProducer {
@Autowired
private AmqpTemplate amqpTemplate;

public void send(String queueName) {
JSONObject jsonObject = new JSONObject();
jsonObject.put("email", "xx@163.com");
jsonObject.put("timestamp", System.currentTimeMillis());
String jsonString = jsonObject.toJSONString();
System.out.println("jsonString:" + jsonString);
// 设置消息唯一id 保证每次重试消息id唯一
/*Message message = MessageBuilder.withBody(jsonString.getBytes())
.setContentType(MessageProperties.CONTENT_TYPE_JSON).setContentEncoding("utf-8")
.setMessageId(UUID.randomUUID() + "").build();*/
amqpTemplate.convertAndSend(queueName, jsonString);
}
}
Controller:

package com.itmayiedu.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.itmayiedu.rabbitmq.FanoutProducer;

@RestController
public class ProducerController {
@Autowired
private FanoutProducer fanoutProducer;

@RequestMapping("/sendFanout")
public String sendFanout(String queueName) {
fanoutProducer.send(queueName);
return "success";
}
}
yml:

spring:
rabbitmq:
####连接地址
host: 192.168.91.6
####端口号
port: 5672
####账号
username: admin
####密码
password: admin
### 地址
virtual-host: /admin_toov5
启动类：

package com.itmayiedu;

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

@SpringBootApplication
public class AppProducer {

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

}

Consumer：

pom:

<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.itmayiedu</groupId>
<artifactId>rabbitmq_consumer_springboot</artifactId>
<version>0.0.1-SNAPSHOT</version>

<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.0.RELEASE</version>
</parent>
<dependencies>

<!-- springboot-web组件 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- 添加springboot对amqp的支持 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-amqp</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mail</artifactId>
</dependency>

<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency>
<!--fastjson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.49</version>
</dependency>

</dependencies>
</project>

utils:

package com.itmayiedu.rabbitmq.utils;

import com.alibaba.fastjson.JSONObject;
import org.apache.http.HttpEntity;
import org.apache.http.HttpStatus;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;

/**
* HttpClient4.3工具类
*
* @author hang.luo
*/
public class HttpClientUtils {
private static Logger logger = LoggerFactory.getLogger(HttpClientUtils.class); // 日志记录

private static RequestConfig requestConfig = null;

static {
// 设置请求和传输超时时间
requestConfig = RequestConfig.custom().setSocketTimeout(2000).setConnectTimeout(2000).build();
}

/**
* post请求传输json参数
*
* @param url
* url地址
* @param json
* 参数
* @return
*/
public static JSONObject httpPost(String url, JSONObject jsonParam) {
// post请求返回结果
CloseableHttpClient httpClient = HttpClients.createDefault();
JSONObject jsonResult = null;
HttpPost httpPost = new HttpPost(url);
// 设置请求和传输超时时间
httpPost.setConfig(requestConfig);
try {
if (null != jsonParam) {
// 解决中文乱码问题
StringEntity entity = new StringEntity(jsonParam.toString(), "utf-8");
entity.setContentEncoding("UTF-8");
entity.setContentType("application/json");
httpPost.setEntity(entity);
}
CloseableHttpResponse result = httpClient.execute(httpPost);
// 请求发送成功，并得到响应
if (result.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
String str = "";
try {
// 读取服务器返回过来的json字符串数据
str = EntityUtils.toString(result.getEntity(), "utf-8");
// 把json字符串转换成json对象
jsonResult = JSONObject.parseObject(str);
} catch (Exception e) {
logger.error("post请求提交失败:" + url, e);
}
}
} catch (IOException e) {
logger.error("post请求提交失败:" + url, e);
} finally {
httpPost.releaseConnection();
}
return jsonResult;
}

/**
* post请求传输String参数 例如：name=Jack&sex=1&type=2
* Content-type:application/x-www-form-urlencoded
*
* @param url
* url地址
* @param strParam
* 参数
* @return
*/
public static JSONObject httpPost(String url, String strParam) {
// post请求返回结果
CloseableHttpClient httpClient = HttpClients.createDefault();
JSONObject jsonResult = null;
HttpPost httpPost = new HttpPost(url);
httpPost.setConfig(requestConfig);
try {
if (null != strParam) {
// 解决中文乱码问题
StringEntity entity = new StringEntity(strParam, "utf-8");
entity.setContentEncoding("UTF-8");
entity.setContentType("application/x-www-form-urlencoded");
httpPost.setEntity(entity);
}
CloseableHttpResponse result = httpClient.execute(httpPost);
// 请求发送成功，并得到响应
if (result.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
String str = "";
try {
// 读取服务器返回过来的json字符串数据
str = EntityUtils.toString(result.getEntity(), "utf-8");
// 把json字符串转换成json对象
jsonResult = JSONObject.parseObject(str);
} catch (Exception e) {
logger.error("post请求提交失败:" + url, e);
}
}
} catch (IOException e) {
logger.error("post请求提交失败:" + url, e);
} finally {
httpPost.releaseConnection();
}
return jsonResult;
}

/**
* 发送get请求
*
* @param url
* 路径
* @return
*/
public static JSONObject httpGet(String url) {
// get请求返回结果
JSONObject jsonResult = null;
CloseableHttpClient client = HttpClients.createDefault();
// 发送get请求
HttpGet request = new HttpGet(url);
request.setConfig(requestConfig);
try {
CloseableHttpResponse response = client.execute(request);

// 请求发送成功，并得到响应
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
// 读取服务器返回过来的json字符串数据
HttpEntity entity = response.getEntity();
String strResult = EntityUtils.toString(entity, "utf-8");
// 把json字符串转换成json对象
jsonResult = JSONObject.parseObject(strResult);
} else {
logger.error("get请求提交失败:" + url);
}
} catch (IOException e) {
logger.error("get请求提交失败:" + url, e);
} finally {
request.releaseConnection();
}
return jsonResult;
}

}
consumer:

package com.itmayiedu.rabbitmq;

import java.util.Map;

import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.amqp.support.AmqpHeaders;
import org.springframework.messaging.handler.annotation.Headers;
import org.springframework.stereotype.Component;

import com.alibaba.fastjson.JSONObject;
import com.itmayiedu.rabbitmq.utils.HttpClientUtils;
import com.rabbitmq.client.Channel;

//邮件队列
@Component
public class FanoutEamilConsumer {
@RabbitListener(queues = "fanout_email_queue")
public void process(String msg) throws Exception {
System.out.println("邮件消费者获取生产者消息msg:" + msg);
JSONObject jsonObject = JSONObject.parseObject(msg);
// 获取email参数
String email = jsonObject.getString("email");
// 请求地址
String emailUrl = "http://127.0.0.1:8083/sendEmail?email=" + email;
JSONObject result = HttpClientUtils.httpGet(emailUrl);
if (result == null) {
// 因为网络原因,造成无法访问,继续重试
throw new Exception("调用接口失败!");
}
System.out.println("执行结束....");

}
}
yml:

spring:
rabbitmq:
####连接地址
host: 192.168.91.6
####端口号
port: 5672
####账号
username: admin
####密码
password: admin
### 地址
virtual-host: /admin_toov5
listener:
simple:
retry:
####开启消费者异常重试
enabled: true
####最大重试次数
max-attempts: 5
####重试间隔次数
initial-interval: 2000

server:
port: 8081

启动类：

package com.itmayiedu.rabbitmq;

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

@SpringBootApplication
public class AppConsumer {

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

}

邮件服务器：

package com.mayikt.controller;

import java.util.HashMap;
import java.util.Map;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@RestController
public class MsgController {

// 模拟第三方发送邮件
@RequestMapping("/sendEmail")
public Map<String, Object> sendEmail(String email) {
System.out.println("开始发送邮件:" + email);
Map<String, Object> result = new HashMap<String, Object>();
result.put("code", "200");
result.put("msg", "发送邮件成功..");
System.out.println("发送邮件成功");
return result;
}

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

}
yml:

server:
port: 8083
pom:

<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.mayikt</groupId>
<artifactId>mayikt_sms</artifactId>
<version>0.0.1-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.0.RELEASE</version>
</parent>
<dependencies>

<!-- springboot-web组件 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- 添加springboot对amqp的支持 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-amqp</artifactId>
</dependency>

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mail</artifactId>
</dependency>

<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency>
<!--fastjson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.49</version>
</dependency>

</dependencies>
</project>
在没有启动邮件服务器时候，消费者 调用接口失败 会一直重试 重试五次

在此期间 如果启动成功 则重试成功 不再重试  不再进行补偿机制

消费者如果保证消息幂等性，不被重复消费

产生原因:网络延迟传输中，或者消费出现异常或者是消费延迟，会造成进行MQ重试进行重试补偿机制，在重试过程中，可能会造成重复消费。

解决办法:

使用全局MessageID判断消费方使用同一个，解决幂等性。

只要重试过程中，判断如果已经走完了 不能再继续走 继续执行了

MQ消费者的幂等行的解决 一般使用全局ID  或者写个唯一标识比如时间戳   或者UUID  或者订单号

改进：

producer：

添加：

// 设置消息唯一id 保证每次重试消息id唯一
Message message = MessageBuilder.withBody(jsonString.getBytes())
.setContentType(MessageProperties.CONTENT_TYPE_JSON).setContentEncoding("utf-8")
.setMessageId(UUID.randomUUID() + "").build(); //消息id设置在请求头里面 用UUID做全局ID
amqpTemplate.convertAndSend(queueName, message);

全部代码：

package com.itmayiedu.rabbitmq;

import java.util.UUID;

import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageBuilder;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.alibaba.fastjson.JSONObject;

@Component
public class FanoutProducer {
@Autowired
private AmqpTemplate amqpTemplate;

public void send(String queueName) {
JSONObject jsonObject = new JSONObject();
jsonObject.put("email", "xx@163.com");
jsonObject.put("timestamp", System.currentTimeMillis());
String jsonString = jsonObject.toJSONString();
System.out.println("jsonString:" + jsonString);
// 设置消息唯一id 保证每次重试消息id唯一
Message message = MessageBuilder.withBody(jsonString.getBytes())
.setContentType(MessageProperties.CONTENT_TYPE_JSON).setContentEncoding("utf-8")
.setMessageId(UUID.randomUUID() + "").build(); //消息id设置在请求头里面 用UUID做全局ID
amqpTemplate.convertAndSend(queueName, message);
}
}

同样的 消费者也需要修改：

方法参数类型为 Message  然后可以获取这个ID 然后可以进行业务逻辑操作

@RabbitListener(queues = "fanout_email_queue")
public void process(Message message) throws Exception {
// 获取消息Id
String messageId = message.getMessageProperties().getMessageId(); //id获取之
String msg = new String(message.getBody(), "UTF-8"); //消息内容获取之
System.out.println("-----邮件消费者获取生产者消息-----------------" + "messageId:" + messageId + ",消息内容:" +
msg);
if (messageId == null) {
return;
}
JSONObject jsonObject = JSONObject.parseObject(msg);
// 获取email参数
String email = jsonObject.getString("email");
// 请求地址
String emailUrl = "http://127.0.0.1:8083/sendEmail?email=" + email;
JSONObject result = HttpClientUtils.httpGet(emailUrl);
if (result == null) {
// 因为网络原因,造成无法访问,继续重试
throw new Exception("调用接口失败!");
}
System.out.println("执行结束....");
//messId 的情况写入到redis 中 成功就修改为空
}

重试机制都是间隔性的  每次都是一个线程  单线程重试

关于应答模式：

Spring boot 中进行 AOP拦截 自动帮助做重试

手动应答的话 ，如果不告诉服务器已经消费成功，则服务器不会删除 消息。告诉消费成功了才会删除。

消费者的yml加入：

acknowledge-mode: manual

spring:
rabbitmq:
####连接地址
host: 192.168.91.6
####端口号
port: 5672
####账号
username: admin
####密码
password: admin
### 地址
virtual-host: /admin_toov5
listener:
simple:
retry:
####开启消费者异常重试
enabled: true
####最大重试次数
max-attempts: 5
####重试间隔次数
initial-interval: 2000
####开启手动ack
acknowledge-mode: manual

server:
port: 8081

开启模式之后：

消费者参数需要加入：  @Headers Map<String, Object> headers, Channel channel

代码逻辑最后面加入：

// // 手动ack
Long deliveryTag = (Long) headers.get(AmqpHeaders.DELIVERY_TAG);
// 手动签收  告诉RabbitMQ 消费成功了  消息可以删除了
channel.basicAck(deliveryTag, false);

代码如下：

@RabbitListener(queues = "fanout_email_queue")
public void process(Message message, @Headers Map<String, Object> headers, Channel channel) throws Exception {
// 获取消息Id
String messageId = message.getMessageProperties().getMessageId();
String msg = new String(message.getBody(), "UTF-8");
System.out.println("邮件消费者获取生产者消息" + "messageId:" + messageId + ",消息内容:" + msg);
JSONObject jsonObject = JSONObject.parseObject(msg);
// 获取email参数
String email = jsonObject.getString("email");
// 请求地址
String emailUrl = "http://127.0.0.1:8083/sendEmail?email=" + email;
JSONObject result = HttpClientUtils.httpGet(emailUrl);
if (result == null) {
// 因为网络原因,造成无法访问,继续重试
throw new Exception("调用接口失败!");
}
// // 手动ack
Long deliveryTag = (Long) headers.get(AmqpHeaders.DELIVERY_TAG);
// 手动签收
channel.basicAck(deliveryTag, false);
System.out.println("执行结束....");
}

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原文链接：https://blog.csdn.net/art_code/article/details/90509689