redis实现分布式锁1

package com.hmdp.utils;public interface ILock {    // 获取锁    boolean tryLock(long timeoutSec);    // 释放锁    void unlock();}

package com.hmdp.utils;import org.springframework.data.redis.core.StringRedisTemplate;import java.util.concurrent.TimeUnit;public class SimpleRedisLock implements ILock {    private String name;    private StringRedisTemplate stringRedisTemplate;    private static final String KEY_PREFIX = "lock:";    public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {        this.name = name;        this.stringRedisTemplate = stringRedisTemplate;    }    @Override    public boolean tryLock(long timeoutSec) {        // 获取线程的标识        long threadId = Thread.currentThread().getId();        // 获取锁        Boolean success = stringRedisTemplate.opsForValue().setIfAbsent(KEY_PREFIX + name, threadId + "", timeoutSec, TimeUnit.SECONDS);        return Boolean.TRUE.equals(success);    }    @Override    public void unlock() {        // 释放锁        stringRedisTemplate.delete(KEY_PREFIX + name);    }}

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.SimpleRedisLock;import com.hmdp.utils.UserHolder;import org.springframework.aop.framework.AopContext;import org.springframework.data.redis.core.StringRedisTemplate;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 */@Servicepublic class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {    @Resource    private ISeckillVoucherService seckillVoucherService;    @Resource    private RedisIdWorker redisIdWorker;    @Resource    private StringRedisTemplate stringRedisTemplate;    @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);        // 获取锁        boolean isLock = lock.tryLock(1200);        // 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();        }    }    @Transactional    public  Result createVoucherOrder(Long voucherId) {        // 5.一人一单        Long userId = UserHolder.getUser().getId();        // 5.1 查询订单        int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();        // 5.2 判断是否存在        if(count > 0){            // 用户已经购买过了            return Result.fail("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", voucherId)//                .eq("stock",voucher.getStock()) // where id = ? and stock = ?                .gt("stock",0) // where id = ? and stock > 0                .update();        if(!success){            return Result.fail("库存不足");        }        // 7.创建订单        VoucherOrder voucherOrder = new VoucherOrder();        // 7.1订单id        long orderId = redisIdWorker.nextId("order");        voucherOrder.setId(orderId);        // 7.2用户id        voucherOrder.setUserId(userId);        // 7.3代金券id        voucherOrder.setVoucherId(voucherId);        save(voucherOrder);        // 8.返回订单id        return Result.ok(orderId);    }}