redis优化秒杀

---
--- Generated by EmmyLua(https://github.com/EmmyLua)
--- Created by 34650.
--- DateTime: 2025/12/30 下午8:29
---local voucherId = ARGV[1]
local userId = ARGV[2]local stockKey = 'seckill:stock:' .. voucherIdlocal orderKey = 'seckill:order:' .. voucherId
-- 判断库存是否充足
if(tonumber(redis.call('get',stockKey)) <=0) thenreturn 1
end
-- 判断用户是否下单
if(redis.call('sismember',orderKey,userId) ==1) thenreturn 2
end
--扣库存
redis.call('incrby',stockKey,-1)
--下单（保存用户）
redis.call('sadd',orderKey,userId)return 0

package com.hmdp.service.impl;import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.Collections;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;/*** <p>*  服务实现类* </p>** @author ztn* @since 2025-09-23*/
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {@Resourceprivate ISeckillVoucherService seckillVoucherService;@Resourceprivate RedisIdWorker redisIdWorker;@Resourceprivate StringRedisTemplate stringRedisTemplate;@Resourceprivate RedissonClient redissonClient;private static final DefaultRedisScript<Long> SECKILL_SCRIPT;static {SECKILL_SCRIPT = new DefaultRedisScript<>();SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));SECKILL_SCRIPT.setResultType(Long.class);}private final BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);private final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();@PostConstructprivate void init(){SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());}private class VoucherOrderHandler implements Runnable {@Overridepublic void run() {while (true) {try {// 1.获取队列中的订单VoucherOrder voucherOrder = orderTasks.take();// 2.创建订单handleVoucherOrder(voucherOrder);} catch (InterruptedException e) {log.error("处理订单异常",e);}}}}private void handleVoucherOrder(VoucherOrder voucherOrder) {// 获取用户Long userId = voucherOrder.getUserId();//创建锁对象
//        SimpleRedisLock lock = 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，返回错误或重试log.error("不允许重复下单");}try {proxy.createVoucherOrder(voucherOrder);}finally {// 释放锁lock.unlock();}}private IVoucherOrderService proxy;@Overridepublic Result seckillVocher(Long voucherId) {//获取用户Long userId = UserHolder.getUser().getId();//执行lua脚本Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,Collections.emptyList(),voucherId.toString(),userId.toString());//判断结果是否为0int r =result.intValue();if(r !=0){return Result.fail(r ==1?"库存不足":"不能重复下单");}//为0，有购买资格，把下单信息保存到阻塞队列VoucherOrder voucherOrder = new VoucherOrder();long orderId = redisIdWorker.nextId("order");voucherOrder.setId(orderId);voucherOrder.setUserId(userId);voucherOrder.setVoucherId(voucherId);//创建阻塞队列orderTasks.add(voucherOrder);// 获取代理对象（事务）proxy = (IVoucherOrderService) AopContext.currentProxy();//返回订单idreturn Result.ok(orderId);}
//    @Override
//    public Result seckillVocher(Long voucherId) {
//        // 1.查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        // 2.判断秒杀是否开始
//        if(voucher.getBeginTime().isAfter(LocalDateTime.now())){
//            return Result.fail("秒杀尚未开始");
//        }
//        // 3.判断秒杀是否结束
//        if(voucher.getEndTime().isBefore(LocalDateTime.now())){
//            return Result.fail("秒杀已经结束");
//        }
//        // 4.判断库是否充足
//        if(voucher.getStock() < 1){
//            return Result.fail("库存不足");
//        }
//
//        Long userId = UserHolder.getUser().getId();
//        // 创建锁对象
////        SimpleRedisLock lock = 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，返回错误或重试
//            return Result.fail("不允许重复下单");
//        }
//        try {
//            // 获取代理对象（事务）
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVoucherOrder(voucherId);
//        }finally {
//            // 释放锁
//            lock.unlock();
//        }
//    }@Transactionalpublic void createVoucherOrder(VoucherOrder voucherOrder) {// 5.一人一单Long userId = voucherOrder.getUserId();// 5.1 查询订单int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder).count();// 5.2 判断是否存在if(count > 0){// 用户已经购买过了log.error("用户已经购买过一次了");}// 6.扣减库存boolean success = seckillVoucherService.update().setSql("stock = stock - 1") // set stock =stock -1.eq("voucher_id", voucherOrder)
//                .eq("stock",voucher.getStock()) // where id = ? and stock = ?.gt("stock",0) // where id = ? and stock > 0.update();if(!success){log.error("库存不足");}save(voucherOrder);}
}