redis实现秒杀下单的业务逻辑

业务逻辑：

具体代码：

package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
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.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author ztn
 * @since 2025-09-23
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;


    @Override
    @Transactional
    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");
        }
        // 5.扣减库存
        boolean success = seckillVoucherService.update().setSql("stock = stock - 1")
                .eq("voucher_id", voucherId).update();

        if(!success){
            return Result.fail("库存不足");
        }
        // 6.创建订单v
        VoucherOrder voucherOrder = new VoucherOrder();
        // 6.1订单id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        // 6.2用户id
        Long userId = UserHolder.getUser().getId();
        voucherOrder.setUserId(userId);
        // 6.3代金券id
        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);
        // 7.返回订单id
        return Result.ok(orderId);
    }
}