我要评论核心：避免超卖问题，保证一人一单 业务逻辑
代码步骤分析
全部代码
@service
public class voucherorderserviceimpl extends serviceimpl<voucherordermapper, voucherorder> implements ivoucherorderservice {
@resource
private iseckillvoucherservice seckillvoucherservice;
@resource
private redisidworker redisidworker;
@resource
private stringredistemplate stringredistemplate;
@resource
private redissonclient redissonclient;
@override
public result seckillvoucher(long voucherid) {
//1 查询优惠券信息
seckillvoucher seckillvoucher = seckillvoucherservice.getbyid(voucherid);
//2 判断秒杀是否开始
localdatetime now = localdatetime.now(); //现在时间
localdatetime begintime = seckillvoucher.getbegintime(); //开始时间
localdatetime endtime = seckillvoucher.getendtime(); //结束时间
if (now.isbefore(begintime)) {
return result.fail("秒杀还未开始");
}
//3 判断秒杀是否结束
if (now.isafter(endtime)) {
return result.fail("秒杀已结束");
}
//4 判断库存是否充足
int stock = (int) seckillvoucher.getstock();
if (stock == 0 && stock <= 0) {
return result.fail("库存不足");
}
//确保一人一单 用户id和代金券id联合查询
long userid = userholder.getuser().getid();
//先获取锁 再提交事务
//synchronized (userid.tostring().intern()) {
//创建锁对象
//simpleredislock simpleredislock = new simpleredislock("order:" + userid, stringredistemplate);
rlock lock = redissonclient.getlock("lock:order:" + userid);
//获取锁
boolean islock = lock.trylock();
//判断是否获取锁成功
if (!islock){
//获取锁失败 返回错误或失败
return result.fail("不允许重复下单");
}
try {
//获取事务的代理对象
ivoucherorderservice proxy = (ivoucherorderservice) aopcontext.currentproxy();
return proxy.creatvoucherorder(voucherid);
} finally {
//释放锁
lock.unlock();
}
//}//事务提交之后在释放锁
}
/**
* 这里对于加锁做出一些解释：如果锁加在整个方法上，那么就会导
* 致锁的粒度过大，导致每个进程进来都会锁住，所以要控制锁的粒度
*/
@transactional
public result creatvoucherorder(long voucherid) {
long userid = userholder.getuser().getid();
integer count = query().eq("user_id", userid).eq("voucher_id", voucherid).count();
if (count > 0) {
return result.fail("用户已经购买过了");
}
//5 扣减库存-
boolean success = seckillvoucherservice.update()
.setsql("stock = stock -1 ") //乐观锁
.eq("voucher_id", voucherid).gt("stock", 0) //判断库存是否大于0: where id = ? and stock > 0
.update();
if (!success) {
return result.fail("库存不足");
}
//6 创建订单
//6.1 订单id
voucherorder voucherorder = new voucherorder();
long orderid = redisidworker.nextid("order");
voucherorder.setvoucherid(orderid);
//6.2 用户id
voucherorder.setuserid(userid);
//6.3 代金券id
voucherorder.setvoucherid(voucherid);
save(voucherorder);
//7 返回订单id
return result.ok(orderid);
}
}
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