// 分布式鎖服務(wù)
public interface RedisLockService {
    // 獲取鎖
    public boolean getLock(String key);
    // 釋放鎖
    public boolean releaseLock(String key);
}

// 業(yè)務(wù)服務(wù)
public class BizService {

    @Resource
    private RedisLockService redisLockService;

    public void bizMethod(String bizId) {
        try {
            // 獲取鎖
            if(redisLockService.getLock(bizId)) {
                // 業(yè)務(wù)重復(fù)校驗
                if(!bizValidate(bizId)) {
                    throw new BizException(ErrorBizCode.REPEATED);
                }
                // 執(zhí)行業(yè)務(wù)
                return doBusiness();
            }
            // 獲取鎖失敗
            throw new BizException(ErrorBizCode.GET_LOCK_ERROR);
        } finally {
            // 釋放鎖
            redisLockService.releaseLock(bizId);
        }
    }
}

public class BizService {

    @Resource
    private RedisLockService redisLockService;

    public void bizMethod(String bizId) {
        boolean getLockSuccess = false;
        try {
            // 嘗試獲取鎖
            getLockSuccess = redisLockService.getLock(bizId);
            // 獲取鎖成功
            if(getLockSuccess) {
                // 業(yè)務(wù)重復(fù)校驗
                if(!bizValidate(bizId)) {
                    throw new BizException(ErrorBizCode.REPEATED);
                }
                // 執(zhí)行業(yè)務(wù)
                return doBusiness();
            }
            // 獲取鎖失敗
            throw new BizException(ErrorBizCode.GET_LOCK_ERROR);
        } finally {
            // 獲取鎖成功才允許釋放鎖
            if(getLockSuccess) {
                redisLockService.releaseLock(bizId);
            }
        }
    }
}

udpate goods set stock = stock - #{acquire} 
where sku_id = #{skuId} and stock - #{acquire} >= 0