通过异步使用消息队列优化秒杀 - ToB企服应用市场:ToB评测及商务社交产业平台

public Result seckillVoucher(Long voucherId) throws InterruptedException {
SeckillVoucher seckillVoucher = iSeckillVoucherService.getById(voucherId);
LocalDateTime beginTime = seckillVoucher.getBeginTime();
if (LocalDateTime.now().isBefore(beginTime)) {
return Result.fail("秒杀还未开始");
}
LocalDateTime endTime = seckillVoucher.getEndTime();
if (LocalDateTime.now().isAfter(endTime)) {
return Result.fail("秒杀已经结束");
}
// 查看库存
Integer stock = seckillVoucher.getStock();
if (stock < 1) {
return Result.fail("库存不足");
}
Long userId = UserHolder.getUser().getId();
// redis集群实现
RLock lock = redissonClient.getLock("order:" + userId);
boolean isLock = lock.tryLock(1L, TimeUnit.SECONDS);
if (!isLock) {
return Result.fail("你已经购买优惠卷");
}
try {
IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
return proxy.createVoucherOrder(voucherId, userId);
} finally {
// redisLock.releaseLock();
lock.unlock();
}
}
@Transactional
public Result createVoucherOrder(Long voucherId, Long userId) {
Integer count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
if (count > 0) {
return Result.fail("已经购买优惠卷");
}
// 基于乐观锁避免超卖问题，在乐观锁的基础上做出了改进，当要修改库存时判断库存是否大于0，但是也给数据库带来了巨大的压力
boolean success = iSeckillVoucherService.update().setSql("stock=stock-1")
.eq("voucher_id", voucherId).
gt("stock", 0).update();
if (!success) {
return Result.fail("库存不足");
}
VoucherOrder voucherOrder = new VoucherOrder();
long orderId = redisWorker.getGlobalId("order");
voucherOrder.setId(orderId);
voucherOrder.setVoucherId(voucherId);
voucherOrder.setUserId(userId);
save(voucherOrder);
return Result.ok(orderId);
}

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--优惠卷id
local voucherId = ARGV[1];
--用户id
local userId = ARGV[2];
--库存键
local stockKey = "voucher:stock:" + voucherId;
--下过订单的用户键
local orderKey = "voucher:order:" + voucherId;
--查看卷库存是否足够
if (tonumber(redis.call("get", stockKey)) <= 0) then
return 1;
end
if (redis.call("sismember",orderKey,userId)==1) then
return 2
end
--扣库存
redis.call("incrby",stockKey,-1);
--添加用户id
redis.call("sadd",orderKey,userId)
return 0

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/**
* 异步秒杀
*/
@Override
public Result seckillVoucher(Long voucherId) throws InterruptedException {
Long userId = UserHolder.getUser().getId();
Long result = redisTemplate.execute(SECkILL_SCRIPT, Collections.emptyList(), voucherId.toString(), userId.toString());
int re = result.intValue();
if (re != 0) {
return re == 1 ? Result.fail("库存不足") : Result.fail("不能重复下单");
}
long orderId = redisWorker.getGlobalId("voucher:order");
VoucherOrder voucherOrder = new VoucherOrder();
voucherOrder.setVoucherId(voucherId);
voucherOrder.setId(orderId);
voucherOrder.setUserId(userId);
VOUCHER_PROXY = (IVoucherOrderService) AopContext.currentProxy();
BLOCKING_QUEUE.add(voucherOrder);
return Result.ok(orderId);
}

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// 初始化lua脚本环境
private static final DefaultRedisScript<Long> SECkILL_SCRIPT;
static {
SECkILL_SCRIPT = new DefaultRedisScript<>();
SECkILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
SECkILL_SCRIPT.setResultType(Long.class);
}
// 在类初始化完之后执行
@PostConstruct
private void init() {
EXECUTOR_SERVICE.execute(new VoucherHandler());
}
// 阻塞队列获取任务处理
private class VoucherHandler implements Runnable {
@Override
public void run() {
while (true){
try {
// 从阻塞队列中获取订单信息
VoucherOrder voucherOrder = BLOCKING_QUEUE.take();
// 更新数据库库存以及创建优惠卷订单
VOUCHER_PROXY.createVoucherOrder(voucherOrder.getVoucherId(), voucherOrder.getUserId());
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
@Transactional
public Result createVoucherOrder(Long voucherId, Long userId) {
Integer count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
if (count > 0) {
return Result.fail("已经购买优惠卷");
}
// 基于乐观锁避免超卖问题，在乐观锁的基础上做出了改进，当要修改库存时判断库存是否大于0，但是也给数据库带来了巨大的压力
boolean success = iSeckillVoucherService.update().setSql("stock=stock-1")
.eq("voucher_id", voucherId).
gt("stock", 0).update();
if (!success) {
return Result.fail("库存不足");
}
VoucherOrder voucherOrder = new VoucherOrder();
long orderId = redisWorker.getGlobalId("order");
voucherOrder.setId(orderId);
voucherOrder.setVoucherId(voucherId);
voucherOrder.setUserId(userId);
save(voucherOrder);
return Result.ok(orderId);
}

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