本篇博客的RocketMq版本为4.3.0，首先附上RocketMq事务消息的流程图，以下的实践也都是基于此流程图
生产端项目
RocketMqConfig配置生产者
package com.yj.producer.config;
import org.apache.rocketmq.client.producer.TransactionMQProducer;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.yj.producer.listener.MyTransactionListener;
@Configuration
public class RocketMqConfig {
@Value("${rocketmq.producer.groupName}")
private String producerGroupName;
@Value("${rocketmq.namesrv.addr}")
private String nameServerAddress;
@Bean(initMethod = "start", destroyMethod = "shutdown")
public TransactionMQProducer producer(MyTransactionListener myTransactionListener) {
TransactionMQProducer producer = new TransactionMQProducer(producerGroupName);
// VipChannel阿里内部使用版本才用，开源版本没有，默认为true，占用10909端口，此时虚拟机需要开放10909端口，否则会报
// ：connect to <：10909> failed异常，可以直接设置为false
// producer.setVipChannelEnabled(false);
producer.setNamesrvAddr(nameServerAddress);
producer.setTransactionListener(myTransactionListener);
return producer;
}
}
MyTransactionListener事务监听器，主要有两个方法，一个执行本地事务的方法，一个提供给MqServer进行消息状态回查的方法，对于上面的流程图中的步骤③和⑥
package com.yj.producer.listener;
import java.util.HashMap;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.rocketmq.client.producer.LocalTransactionState;
import org.apache.rocketmq.client.producer.TransactionListener;
import org.apache.rocketmq.common.message.Message;
import org.apache.rocketmq.common.message.MessageExt;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.yj.producer.model.MsgStatus;
import com.yj.producer.service.AccountService;
@Component
public class MyTransactionListener implements TransactionListener {
private static final Logger log = LoggerFactory.getLogger(MyTransactionListener.class);
@Autowired
private AccountService accountService;
private ConcurrentHashMap<String, Integer> transStatusMap = new ConcurrentHashMap<>();
@Override
public LocalTransactionState executeLocalTransaction(Message msg, Object arg) {
String transactionId = msg.getTransactionId();
log.info("准备开始更新账户,当前状态为:"+MsgStatus.UNKNOW);
transStatusMap.put(transactionId, MsgStatus.UNKNOW.getStatus());
HashMap<String, Object> map = (HashMap<String, Object>) arg;
long userId = (long) map.get("user_id");
long productId = (long) map.get("product_id");
String errorFlag = (String) map.get("errorFlag");
String timeFlag = (String) map.get("timeFlag");
try {
accountService.updateAccount(userId, productId, errorFlag,timeFlag);
log.info("更新账户成功");
} catch (Exception e) {
log.info("更新账户发生异常,事务回滚,状态为:"+MsgStatus.ROLLBACK);
transStatusMap.put(transactionId, MsgStatus.ROLLBACK.getStatus());
return LocalTransactionState.ROLLBACK_MESSAGE;
}
log.info("更新账户成功,状态为:"+MsgStatus.COMMIT);
transStatusMap.put(transactionId, MsgStatus.COMMIT.getStatus());
return LocalTransactionState.COMMIT_MESSAGE;
}
@Override
public LocalTransactionState checkLocalTransaction(MessageExt msg) {
String transactionId = msg.getTransactionId();
Integer status = transStatusMap.get(transactionId);
if (status == MsgStatus.COMMIT.getStatus()) {
log.info("消息回查,状态为:"+MsgStatus.COMMIT);
return LocalTransactionState.COMMIT_MESSAGE;
} else if (status == MsgStatus.ROLLBACK.getStatus()) {
log.info("消息回查,状态为:"+MsgStatus.ROLLBACK);
return LocalTransactionState.ROLLBACK_MESSAGE;
}
log.info("消息回查,状态为:"+MsgStatus.UNKNOW);
return LocalTransactionState.UNKNOW;
}
}
自定义MQProducer封装生产者发送事务消息的方法
package com.yj.producer.producer;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.client.producer.TransactionMQProducer;
import org.apache.rocketmq.common.message.Message;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.yj.producer.model.BusinessException;
@Component
public class MQProducer {
@Autowired
private TransactionMQProducer producer;
public SendResult sendTranscationMsg(Message message,Object arg) throws BusinessException {
SendResult result = null;
try {
result = producer.sendMessageInTransaction(message, arg);
} catch (Exception e) {
e.printStackTrace();
throw new BusinessException("发送事务消息发生异常");
}
return result;
}
}
AccountService
package com.yj.producer.service;
import java.util.HashMap;
import org.apache.rocketmq.common.message.Message;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.alibaba.fastjson.JSON;
import com.yj.producer.dao.AccountDao;
import com.yj.producer.model.Storage;
import com.yj.producer.producer.MQProducer;
@Service
public class AccountService {
private static final Logger log = LoggerFactory.getLogger(AccountService.class);
@Autowired
private AccountDao accountDao;
@Autowired
private MQProducer producer;
@Value("${rocketmq.topic}")
private String topic;
/**
* 本地事务
*/
@Transactional
public String updateAccount(long userId, long productId, String errorFlag,String timeFlag) {
business(userId, productId, errorFlag,timeFlag);
return "下单成功";
}
public String mqTransaction(long userId, long productId, String errorFlag,String timeFlag) {
Message message = new Message();
message.setTopic(topic);
Storage storage=new Storage();
storage.setProductId(productId);
String storageStr = JSON.toJSONString(storage);
message.setBody(storageStr.getBytes());
message.setTags(productId + "_tag");
HashMap<String,Object> arg=new HashMap<>();
arg.put("user_id", userId);
arg.put("product_id", productId);
arg.put("errorFlag", errorFlag);
arg.put("timeFlag", timeFlag);
producer.sendTranscationMsg(message,arg);
return "下单成功";
}
private void business(long userId, long productId, String errorFlag,String timeFlag) {
log.info("==账户服务扣减账户余额开始==");
accountDao.updateAccount(userId);
if ("1".equals(errorFlag)) {
int i = 1 / 0;
}
if ("1".equals(timeFlag)) {
try {
Thread.sleep(120000L);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
log.info("==账户服务扣减账户余额结束==");
}
}
AccountController
package com.yj.producer.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import com.yj.producer.service.AccountService;
@RestController
public class AccountController {
@Autowired
private AccountService accountService;
@PostMapping("/mqTransaction")
public String mqTransaction(@RequestParam("user_id") long userId, @RequestParam("product_id") long productId,
@RequestParam("errorFlag") String errorFlag, @RequestParam("timeFlag") String timeFlag) {
return accountService.mqTransaction(userId, productId, errorFlag, timeFlag);
}
}
MsgStatus
package com.yj.producer.model;
public enum MsgStatus {
COMMIT(1,"提交"),
ROLLBACK(2,"回滚"),
UNKNOW(3,"未知");
private int status;
private String msg;
private MsgStatus(int status, String msg) {
this.status = status;
this.msg = msg;
}
public int getStatus() {
return status;
}
public String getMsg() {
return msg;
}
}
消费端项目
消费端的配置没有什么特别的地方，可以参考mq顺序消息的消费者的配置，消费端监听到消息后，执行本地事务
package com.yj.consumer.consumer;
import org.apache.rocketmq.common.message.MessageExt;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import com.alibaba.fastjson.JSON;
import com.yj.consumer.model.Storage;
import com.yj.consumer.service.StorageService;
@Service
public class MessageProcessor {
@Value("${server.port}")
private String port;
@Autowired
private StorageService storageService;
private static final Logger LOGGER = LoggerFactory.getLogger(MessageProcessor.class);
public Boolean handleMessage(MessageExt messageExt) {
try {
String body = null;
// 消费者消费
if (null == messageExt || null == messageExt.getBody()) {
LOGGER.info("消息体为空");
return false;
}
body = new String(messageExt.getBody());
Storage storage = JSON.parseObject(body, Storage.class);
LOGGER.info("port:"+port+",消费Tag:" + messageExt.getTags() + ",storage:" + storage);
storageService.updateStorage(storage.getProductId());
} catch (Exception e) {
e.printStackTrace();
LOGGER.error(e.getMessage(), e);
return false;
}
return true;
}
}
StorageService
package com.yj.consumer.service;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.yj.consumer.dao.StorageDao;
@Service
public class StorageService {
private static final Logger log = LoggerFactory.getLogger(StorageService.class);
@Autowired
private StorageDao storageDao;
/**
* 扣减库存
*/
@Transactional
public void updateStorage(long productId) {
log.info("==库存服务扣减库存开始==");
try {
storageDao.updateStorage(productId);
//int i=1/0;
} catch (Exception e) {
log.info("消费方消费时发生异常,此时需人工介入处理");
e.printStackTrace();
}
log.info("==库存服务扣库存结束==");
}
}
启动MQ环境，开始验证
①生产端，消费端均正常的情况
http://127.0.0.1:8001/mqTransaction?user_id=1&product_id=1&errorFlag=0&timeFlag=0
生产方日志
2020-01-28 16:12:34.859 INFO 12580 --- [nio-8001-exec-1] c.y.p.listener.MyTransactionListener : 准备开始更新账户,当前状态为:UNKNOW
2020-01-28 16:12:35.142 INFO 12580 --- [nio-8001-exec-1] com.yj.producer.service.AccountService : ==账户服务扣减账户余额开始==
2020-01-28 16:12:35.163 DEBUG 12580 --- [nio-8001-exec-1] c.y.p.dao.AccountDao.updateAccount : ==> Preparing: update account set money = money-10 where user_id = ?
2020-01-28 16:12:35.266 DEBUG 12580 --- [nio-8001-exec-1] c.y.p.dao.AccountDao.updateAccount : ==> Parameters: 1(Long)
2020-01-28 16:12:35.270 DEBUG 12580 --- [nio-8001-exec-1] c.y.p.dao.AccountDao.updateAccount : <== Updates: 1
2020-01-28 16:12:35.270 INFO 12580 --- [nio-8001-exec-1] com.yj.producer.service.AccountService : ==账户服务扣减账户余额结束==
2020-01-28 16:12:35.276 INFO 12580 --- [nio-8001-exec-1] c.y.p.listener.MyTransactionListener : 更新账户成功
2020-01-28 16:12:35.276 INFO 12580 --- [nio-8001-exec-1] c.y.p.listener.MyTransactionListener : 更新账户成功,状态为:COMMIT
消费方日志
2020-01-28 16:12:35.560 INFO 15628 --- [MessageThread_1] com.yj.consumer.service.StorageService : ==库存服务扣减库存开始==
2020-01-28 16:12:35.575 DEBUG 15628 --- [MessageThread_1] c.y.c.dao.StorageDao.updateStorage : ==> Preparing: update storage set num = num-1 where product_id = ?
2020-01-28 16:12:35.675 DEBUG 15628 --- [MessageThread_1] c.y.c.dao.StorageDao.updateStorage : ==> Parameters: 1(Long)
2020-01-28 16:12:35.682 DEBUG 15628 --- [MessageThread_1] c.y.c.dao.StorageDao.updateStorage : <== Updates: 1
2020-01-28 16:12:35.682 INFO 15628 --- [MessageThread_1] com.yj.consumer.service.StorageService : ==库存服务扣库存结束==
业务正常执行
②生产端执行异常的情况
http://127.0.0.1:8001/mqTransaction?user_id=1&product_id=1&errorFlag=1&timeFlag=0
生产端日志
2020-01-28 16:14:58.768 INFO 12580 --- [nio-8001-exec-3] c.y.p.listener.MyTransactionListener : 准备开始更新账户,当前状态为:UNKNOW
2020-01-28 16:14:58.782 INFO 12580 --- [nio-8001-exec-3] com.yj.producer.service.AccountService : ==账户服务扣减账户余额开始==
2020-01-28 16:14:58.782 DEBUG 12580 --- [nio-8001-exec-3] c.y.p.dao.AccountDao.updateAccount : ==> Preparing: update account set money = money-10 where user_id = ?
2020-01-28 16:14:58.783 DEBUG 12580 --- [nio-8001-exec-3] c.y.p.dao.AccountDao.updateAccount : ==> Parameters: 1(Long)
2020-01-28 16:14:58.786 DEBUG 12580 --- [nio-8001-exec-3] c.y.p.dao.AccountDao.updateAccount : <== Updates: 1
2020-01-28 16:14:58.813 INFO 12580 --- [nio-8001-exec-3] c.y.p.listener.MyTransactionListener : 更新账户发生异常,事务回滚,状态为:ROLLBACK
消费端没有接收到消息，无日志输出
③生产端执行超时的情况
生产端日志，发现进行了消息的回查
2020-01-28 16:18:57.914 INFO 3852 --- [nio-8001-exec-1] c.y.p.listener.MyTransactionListener : 准备开始更新账户,当前状态为:UNKNOW
2020-01-28 16:18:58.222 INFO 3852 --- [nio-8001-exec-1] com.yj.producer.service.AccountService : ==账户服务扣减账户余额开始==
2020-01-28 16:18:58.238 DEBUG 3852 --- [nio-8001-exec-1] c.y.p.dao.AccountDao.updateAccount : ==> Preparing: update account set money = money-10 where user_id = ?
2020-01-28 16:18:58.367 DEBUG 3852 --- [nio-8001-exec-1] c.y.p.dao.AccountDao.updateAccount : ==> Parameters: 1(Long)
2020-01-28 16:18:58.371 DEBUG 3852 --- [nio-8001-exec-1] c.y.p.dao.AccountDao.updateAccount : <== Updates: 1
2020-01-28 16:20:16.033 INFO 3852 --- [pool-1-thread-1] c.y.p.listener.MyTransactionListener : 消息回查,状态为:UNKNOW
2020-01-28 16:20:57.938 INFO 3852 --- [lientSelector_1] RocketmqRemoting : closeChannel: close the connection to remote address[192.168.190.131:10909] result: true
2020-01-28 16:20:58.373 INFO 3852 --- [nio-8001-exec-1] com.yj.producer.service.AccountService : ==账户服务扣减账户余额结束==
2020-01-28 16:20:58.376 INFO 3852 --- [nio-8001-exec-1] c.y.p.listener.MyTransactionListener : 更新账户成功
2020-01-28 16:20:58.376 INFO 3852 --- [nio-8001-exec-1] c.y.p.listener.MyTransactionListener : 更新账户成功,状态为:COMMIT
消费端日志，超时结束后，消费端，消费了消息
2020-01-28 16:20:58.382 INFO 15628 --- [MessageThread_2] com.yj.consumer.service.StorageService : ==库存服务扣减库存开始==
2020-01-28 16:20:58.383 DEBUG 15628 --- [MessageThread_2] c.y.c.dao.StorageDao.updateStorage : ==> Preparing: update storage set num = num-1 where product_id = ?
2020-01-28 16:20:58.383 DEBUG 15628 --- [MessageThread_2] c.y.c.dao.StorageDao.updateStorage : ==> Parameters: 1(Long)
2020-01-28 16:20:58.388 DEBUG 15628 --- [MessageThread_2] c.y.c.dao.StorageDao.updateStorage : <== Updates: 1
2020-01-28 16:20:58.388 INFO 15628 --- [MessageThread_2] com.yj.consumer.service.StorageService : ==库存服务扣库存结束==
2020-01-28 16:21:16.052 INFO 15628 --- [MessageThread_3] c.yj.consumer.consumer.MessageProcessor : port:8004,消费Tag:1_tag,storage:Storage(id=0, productId=1, num=null)
2020-01-28 16:21:16.053 INFO 15628 --- [MessageThread_3] com.yj.consumer.service.StorageService : ==库存服务扣减库存开始==
2020-01-28 16:21:16.053 DEBUG 15628 --- [MessageThread_3] c.y.c.dao.StorageDao.updateStorage : ==> Preparing: update storage set num = num-1 where product_id = ?
2020-01-28 16:21:16.053 DEBUG 15628 --- [MessageThread_3] c.y.c.dao.StorageDao.updateStorage : ==> Parameters: 1(Long)
2020-01-28 16:21:16.057 DEBUG 15628 --- [MessageThread_3] c.y.c.dao.StorageDao.updateStorage : <== Updates: 1
2020-01-28 16:21:16.057 INFO 15628 --- [MessageThread_3] com.yj.consumer.service.StorageService : ==库存服务扣库存结束==
④消费端异常的情况
消费端异常的情况下，需人工介入处理。从工程实践角度讲，这种整个流程自动回滚的代价是非常巨大的，不但实现复杂，还会引入新的问题。比如自动回滚失败，又怎么处理？对应这种极低概率的case，采取人工处理，会比实现一个高复杂的自动化回滚系统，更加可靠，也更加简单。
来源：CSDN
作者：猎户星座。
链接：https://blog.csdn.net/qq_24313635/article/details/104100279