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商城积分系统的代码实现（上）-- 积分账户及收支记录

news 2025/6/28 14:46:20

一、背景

上一系列文章，我们说了积分的数模设计及接口设计，接下里，我们将梳理一下具体的代码实现。

使用的语言的java，基本框架是spring-boot，持久化框架则是Jpa。

使用到的技术点有：

分布式锁（积分发放和消耗，在分布式场景下，防止网络重试带来的重复请求问题）
乐观锁（更新积分账户表和积分订单表）
事件驱动机制（积分账户遇有变更，及时通知用户，发送消息提醒）

限于篇幅，我们将分文两篇来讲：

积分账户及收支记录
积分订单的退款和结算

二、积分的收入

用户能够通过三种途径获得积分，发放的核心逻辑是一致的，但三者的前置校验不同。

所以，我们定义三个不同的方法，各自校验完成，统一调用发放积分的方法。

因为涉及多次操作数据库，需要开启事务，并且修改事务的隔离级别为Isolation.READ_COMMITTED，见下代码。（原因见后文的乐观锁实现）

购买虚拟货币/积分

@Lock(name = POINTS_DISTRIBUTE_LOCK_PRE, key = "'buy:orderNo:' + #orderNo")@Transactional(rollbackFor = Throwable.class, isolation = Isolation.READ_COMMITTED)public Long grantByBuy(Integer schoolId, Long userId, String pointsType, Integer points,String orderNo, String remark, String token) {// 查询是否已经发放过，防止重复boolean syncSuccess = this.syncPointsOrder(orderNo, schoolId, userId, pointsType, points);if (!syncSuccess) {return null;}return this.grant(schoolId, userId, PointsChannelEnum.BUY.getCode(), PointsChannelEnum.BUY.getName(),pointsType, points,orderNo, null, remark, token);}

手动发放积分

    @Lock(name = POINTS_DISTRIBUTE_LOCK_PRE, key = "'artificial:userId:' + #userId")@Transactional(rollbackFor = Throwable.class, isolation = Isolation.READ_COMMITTED)public Long grantByArtificial(Integer schoolId, Long userId,String pointsType, Integer points,String optUserId, String remark, String token) {return this.grant(schoolId, userId, PointsChannelEnum.GRANT_BY_HAND.getCode(),PointsChannelEnum.GRANT_BY_HAND.getName(), pointsType, points,null, optUserId, remark, token);}

做任务，获得积分奖励

    @Lock(name = POINTS_DISTRIBUTE_LOCK_PRE, key = "'grant:userId:' + #userId + ':channelCode:' + #channelCode")@Transactional(rollbackFor = Throwable.class, isolation = Isolation.READ_COMMITTED)public Long grantByChannel(Integer schoolId, Long userId,String channelCode, String pointsType,String remark, String token) {// 校验channelCodePointsChannel pointsChannel = pointsChannelRepository.findByCodeAndPointsType(channelCode, pointsType);Precondition.notNull(pointsChannel, "积分渠道[%s]未配置", channelCode);Precondition.isTrue(pointsChannel.getRewardPoints() > 0, "积分渠道配置的积分数必须大于0");return this.grant(schoolId, userId,channelCode, pointsChannel.getName(), pointsType, pointsChannel.getRewardPoints(),null, null, remark, token);}

1、发放积分

除了校验token不能重复使用外，第一步是增加账户的余额，第二步是保存账户的收支记录，第三步是异步通知操作（提醒用户，积分账户有变更，因为非主流程，所以异步，这里采用事件驱动机制）。

private Long grant(Integer schoolId, Long userId,String channelCode, String channelName,String pointsType, Integer rewardPoints,String orderNo, String optUserId, String remark, String token) {if (log.isInfoEnabled()) {log.info("开始发放积分, 入参列表：[schoolId={}, userId={}, channelCode={}, pointsType={}, rewardPoints={}, " +"orderNo={}, optUserId={}, remark={}, token={}]",schoolId, userId, channelCode, pointsType, rewardPoints, orderNo, optUserId, remark, token);}// 校验token不能重复使用（略）//1.账户增加余额PointsAccount pointsAccount = pointsAccountService.findPointsAccount(schoolId, userId, pointsType);if (null == pointsAccount) {// 创建账户pointsAccountService.save(schoolId, userId, pointsType, rewardPoints);} else {boolean updateSuccess = this.optimisticUpdateAccount(GRANT_POINTS_ACCOUNT,pointsAccount.getId(), pointsAccount.getPoints(),rewardPoints, pointsAccount.getVersion());if (!updateSuccess) {if (log.isWarnEnabled()) {log.warn("发放积分出现错误, [schoolId={}, userId={}, channelCode={}, pointsType={}, rewardPoints={}]",schoolId, userId, channelCode, pointsType, rewardPoints);}Precondition.isTrue(false, "发放积分给用户%d出现错误", userId);}}//2.保存账户变更记录PointsAccountFlow flow = pointsAccountFlowService.savePointsAccountFlow(FlowTypeEnum.INCREASE,schoolId, userId, pointsType,rewardPoints, channelCode, channelName,orderNo, optUserId, remark);// 3. 发布异步事件，提醒用户其账户有变更。（略）if (log.isInfoEnabled()) {log.info("完成发放积分, [schoolId={}, userId={}, channelCode={}, pointsType={}, rewardPoints={}, " +"orderNo={}, optUserId={}, remark={}, token={}]",schoolId, userId, channelCode, pointsType, rewardPoints, orderNo, optUserId, remark, token);}return flow.getId();}

2、乐观锁实现账户的变更

乐观更新账户，重试N次，如果更新失败，则再次查询DB最新数据。
我们使用的是mysql数据库，其默认隔离级别是可重复读，所以上文需要指定方法的隔离级别是Isolation.READ_COMMITTED，否则在同一个事务中，读取不到其他事务提交的最新数据。

这是关于数据库的隔离级别，第二点，因为我们使用的jpa持久化框架，它有着著名的一级缓存和二级缓存；所以我们需要手动清除其一级缓存。

    @Autowiredprivate EntityManager entityManager;//清除jpa一级缓存entityManager.clear();

第三点，我们在update行记录的时候，判断version是否一致。

optimisticUpdateAccount()

	private boolean optimisticUpdateAccount(int optType, long accountId, int points, int thisPoints, long version) {int time = 0;boolean success = false;while (time < MAX_RETRY_TIME) {int result = 0;switch (optType) {// 这两种情况是增加余额// 发放积分case GRANT_POINTS_ACCOUNT:// 回退积分case ROLLBACK_POINTS_ACCOUNT:result = pointsAccountService.updateAccountPoints(accountId,points + thisPoints,version);break;// 这两种情况是减少余额// 使用积分case USE_POINTS_ACCOUNT:// 积分订单的退款case REFUND_POINTS_ACCOUNT:result = pointsAccountService.updateAccountPoints(accountId,points - thisPoints,version);break;default:break;}if (result == 1) {success = true;break;}//清除jpa一级缓存entityManager.clear();try {Thread.sleep(100);} catch (InterruptedException e) {log.error("乐观锁更新账户余额中的sleep出现异常", e);}PointsAccount pointsAccount = pointsAccountService.findPointsAccount(accountId);Precondition.notNull(pointsAccount, "积分账户不存在");version = pointsAccount.getVersion();points = pointsAccount.getPoints();time++;}return success;}

modifyAccountPoints()

    @Modifying@Query(value = "update PointsAccount set points = :points, version = version + 1, modifiedDate = now() " +" where id = :id and version = :oldVersion ")int modifyAccountPoints(@Param("id") long id,@Param("points") int points,@Param("oldVersion") long oldVersion);

在这里插入图片描述

三、消耗积分

分为四步：

1、更新账户的余额，保证此次消耗的积分是小于等于账户的余额
2、保存账户变更记录
3、发布异步事件，通知用户其账户变更
4、更新积分订单表：已使用积分数、可用积分数、可结算积分数

关于积分订单表的更新，见下一篇文章。

@Lock(name = POINTS_DISTRIBUTE_LOCK_PRE, key = "'use:orderNo:' + #orderNo")@Transactional(rollbackFor = Throwable.class, isolation = Isolation.READ_COMMITTED)public void use(Integer schoolId, Long userId, String orderNo, String pointsType, Integer points, String remark) {if (log.isInfoEnabled()) {log.info("开始消费积分, 入参列表：[schoolId={}, userId={}, orderNo={}, pointsType={}, points={}, remark={}]",schoolId, userId, orderNo, pointsType, points, remark);}//1.更新账户的余额this.updateAccount(USE_POINTS_ACCOUNT, schoolId, userId, pointsType, points);//2.保存账户变更记录pointsAccountFlowService.savePointsAccountFlow(FlowTypeEnum.DECREASE,schoolId, userId,pointsType, points,PointsChannelEnum.USE.getCode(), PointsChannelEnum.USE.getName(),orderNo, null,remark);//3.发布异步事件，通知用户其账户变更（略）//4.更新积分订单表中的已使用积分数和可用积分数以及可结算积分数// 根据userId/schoolId/pointsType查询可用的的积分，按时间先后顺序扣减订单的可用积分数this.updatePointsOrderByUse(schoolId, userId, pointsType, points);if (log.isInfoEnabled()) {log.info("完成消费积分, [schoolId={}, userId={}, orderNo={}, pointsType={}, points={}, remark={}]",schoolId, userId, orderNo, pointsType, points, remark);}}

四、积分的回退

当商品的定价是纯积分方式，或者积分+现金的组合方式，这类商品发生退款后，我们需要把用户消耗的积分回退其账户。

所谓积分的回退，相当于给用户再次发放等量的积分。

@Lock(name = POINTS_DISTRIBUTE_LOCK_PRE, key = "'rollback:orderNo:' + #orderNo")@Transactional(rollbackFor = Throwable.class, isolation = Isolation.READ_COMMITTED)public void rollback(Integer schoolId, Long userId, String orderNo, String pointsType, Integer points) {if (log.isInfoEnabled()) {log.info("开始回退积分, 入参列表：[schoolId={}, userId={}, orderNo={}, pointsType={}, points={}]",schoolId, userId, orderNo, pointsType, points);}// 仅检查账户是否存在PointsAccount pointsAccount = pointsAccountService.findPointsAccount(schoolId, userId, pointsType);Precondition.isTrue(null != pointsAccount, "积分账户[%d]不存在", userId);//1.把扣除的积分回退到用户的账户余额里boolean updateSuccess = this.optimisticUpdateAccount(ROLLBACK_POINTS_ACCOUNT,pointsAccount.getId(), pointsAccount.getPoints(),points, pointsAccount.getVersion());if (!updateSuccess) {if (log.isWarnEnabled()) {log.warn("回退积分出现错误, [schoolId={}, userId={}, orderNo={}, pointsType={}, points={}]",schoolId, userId, orderNo, pointsType, points);}Precondition.isTrue(false, "回退用户[%d]的积分出现错误", userId);}//2.保存账户变更记录pointsAccountFlowService.savePointsAccountFlow(FlowTypeEnum.INCREASE,schoolId, userId, pointsType,points, PointsChannelEnum.CANCEL_ORDER.getCode(), PointsChannelEnum.CANCEL_ORDER.getName(),orderNo, null, "订单号[" + orderNo + "]取消");//3.发布异步事件，通知用户其账户变更（略）if (log.isInfoEnabled()) {log.info("完成回退积分, [schoolId={}, userId={}, orderNo={}]", schoolId, userId, orderNo);}}