Redis incr生成订单号弊端 利用redis生成订单号

一、实体类与controller层

@Data
public class OrderVo {

	@ApiModelProperty(value = "使用预生产订单号防重")
	private String orderNo;

	@ApiModelProperty(value = "用户id")
	private Long userId;

	@ApiModelProperty(value = "收货人姓名")
	private String receiverName;

	@ApiModelProperty(value = "收货人电话")
	private String receiverPhone;

	@ApiModelProperty(value = "下单选中的优惠券id")
	private Long couponId;

}

@ApiOperation("生成订单")  //swagger注解
@PostMapping("auth/submitOrder")
public Result submitOrder(@RequestBody OrderVo orderVo) {
    Long orderId = orderInfoService.submitOrder(orderVo);
    return Result.ok(orderId);
}

 接口实现类实现细节：

        第一步：获取用户, 确定用户的订单

        第二步：确保订单的唯一性, 订单不能重复提交，重复提交验证，通过redis + lua脚本进行判断

        第三步：lua脚本保证原子性操作

        第四步：验证库存 并且 锁定库存

     示例：比如仓库有5个耳机，我想买2个 验证库存，查询仓库里面是是否有充足耳机 若库存充足，库存锁定 2 （目前没有真正减库存）

 代码中的lua脚本：

String script = "if(redis.call('get', KEYS[1]) == ARGV[1]) then return redis.call('del', KEYS[1]) else return 0 end";

       解释：  如果redis有相同orderNo，表示正常提交订单，把redis的orderNo删除。

                    传入

 具体代码：

@Override
    public Long ordersSubmit(OrderVo orderVo) {
        //获取用户,确定用户的订单
        Long userId = AuthContextHolder.getUserId();
        orderVo.setUserId(userId);
        //确保订单的唯一性,
        String orderNo = orderVo.getOrderNo();
        if (StringUtils.isEmpty(orderNo)) {
            throw new SsyxException(ResultCodeEnum.ILLEGAL_REQUEST);
        }

        // 拿着orderNo 到 redis进行查询,
        String script = "if(redis.call('get', KEYS[1]) == ARGV[1]) then return redis.call('del', KEYS[1]) else return 0 end";
        // 如果redis有相同orderNo，表示正常提交订单，把redis的orderNo删除
        Boolean b = (Boolean) redisTemplate.execute(new DefaultRedisScript(script, boolean.class),
                Arrays.asList(RedisConst.ORDER_REPEAT + orderNo), orderNo);
        if (!b) {
            //重复提交抛出异常
          throw new SsyxException(ResultCodeEnum.REPEAT_SUBMIT);
        }

        //第三步 远程调用cartFeignClient ，验证库存 并且 锁定库存
 
        List<CartInfo> cartInfoList = cartFeignClient.getCartCheckedProduct(userId);

        // 获取普通商品
        List<CartInfo> commonList = cartInfoList.stream()
                .filter(cartInfo -> cartInfo.getSkuType() == SkuType.COMMON.getCode())
                .collect(Collectors.toList());

        //3、把获取购物车里面普通类型商品list集合，List<CartInfo>转换List<SkuStockLockVo>
        if (!CollectionUtils.isEmpty(commonList)) {
            List<SkuStockLockVo> skuStockLockVoList = commonList.stream().map(common -> {
                SkuStockLockVo skuStockLockVo = new SkuStockLockVo();
                BeanUtils.copyProperties(common, skuStockLockVo);
                return skuStockLockVo;
            }).collect(Collectors.toList());

            //4、远程调用service-product模块实现锁定商品
            // 验证库存并锁定库存，保证具备原子性
            Boolean isLockSuccess =
                    productFeignClient.checkLock(skuStockLockVoList, orderNo);
            if(!isLockSuccess) {//库存锁定失败
                throw new SsyxException(ResultCodeEnum.ORDER_STOCK_FALL);
            }
        }

        //第四步 下单步骤
        //1 向两张表添加数据
        // order_info 和 order_item
        Long orderId = this.saveOrder(orderVo,cartInfoList);

        //下单完成，删除购物车记录
        //发送mq消息
        rabbitService.sendMessage(MqConst.EXCHANGE_ORDER_DIRECT,
                MqConst.ROUTING_DELETE_CART,orderVo.getUserId());
        // 返回订单Id

        return orderId;
    }@Data
public class CartInfo extends BaseEntity {

	private static final long serialVersionUID = 1L;

	@ApiModelProperty(value = "用户id")
	private Long userId;

	@ApiModelProperty(value = "分类id")
	private Long categoryId;

	@ApiModelProperty(value = "商品类型：0->普通商品 1->秒杀商品")
	private Integer skuType;

	@ApiModelProperty(value = "是否新人专享：0->否；1->是")
	private Integer isNewPerson;

	@ApiModelProperty(value = "sku名称 (冗余)")
	private String skuName;

	@ApiModelProperty(value = "skuid")
	private Long skuId;

	@ApiModelProperty(value = "放入购物车时价格")
	private BigDecimal cartPrice;

	@ApiModelProperty(value = "数量")
	private Integer skuNum;

	@ApiModelProperty(value = "限购个数")
	private Integer perLimit;

	@ApiModelProperty(value = "图片文件")
	private String imgUrl;

	@ApiModelProperty(value = "isChecked")
	private Integer isChecked;

	@ApiModelProperty(value = "状态")
	private Integer status;

	@ApiModelProperty(value = "秒杀开始时间")
	@JsonFormat(pattern = "HH:mm:ss")
	private Date startTime;

	@ApiModelProperty(value = "秒杀结束时间")
	@JsonFormat(pattern = "HH:mm:ss")
	private Date endTime;

	@ApiModelProperty(value = "仓库")
	private Long wareId;

}@Data
public class SkuStockLockVo implements Serializable {

	@ApiModelProperty(value = "skuId")
	private Long skuId;

	@ApiModelProperty(value = "sku个数")
	private Integer skuNum;

	@ApiModelProperty(value = "是否锁定")
	private Boolean isLock = false;
}

 远程服务 CartFeignClient ：

@FeignClient("service-cart")
public interface CartFeignClient {
    @GetMapping("/cart/getCartCheckedList/{userId}")
    List<CartInfo> getCartCheckedProduct(Long userId);
}

@GetMapping("/cart/getCartCheckedList/{userId}")
    public List<CartInfo> getCartCheckedList(@PathVariable("userId") Long userId) {
        return cartInfoService.getCartCheckedProduct(userId);
    }

//获取当前用户购物车选中购物项
    @Override
    public List<CartInfo> getCartCheckedProduct(Long userId) {
        String cartKey = this.getCartKey(userId);
        BoundHashOperations<String,String,CartInfo> boundHashOperations =
                redisTemplate.boundHashOps(cartKey);
        List<CartInfo> cartInfoProduct = boundHashOperations.values();
        //isChecked = 1表示选中的商品
        List<CartInfo> cartInfoList = cartInfoList.stream()
                .filter(cartInfo -> {
                    return cartInfo.getIsChecked().intValue() == 1;
                }).collect(Collectors.toList());
        return cartInfoList ;
    }

ProductFeginClient 服务具体实现

@FeignClient(value = "service-product")
public interface ProductFeignClient {

    @PostMapping("product/checkAndLock/{orderNo}")
    public  Boolean checkLock(List<SkuStockLockVo> skuStockLockVoList, @PathVariable("orderNo") String orderNo);

}

controller层:  controller中的请求接口要与ProductFeignClient的保持一致

@ApiOperation(value = "锁定库存")
    @PostMapping("product/checkAndLock/{orderNo}")
    public Boolean checkAndLock(@RequestBody List<SkuStockLockVo> skuStockLockVoList,
                                @PathVariable String orderNo) {
        return skuInfoService.checkLock(skuStockLockVoList,orderNo);
    }

//验证和锁定库存
    @Override
    public Boolean checkLock(List<SkuStockLockVo> skuStockLockVoList,
                                String orderNo) {
        //1 判断skuStockLockVoList集合是否为空
        if (CollectionUtils.isEmpty(skuStockLockVoList)) {
            throw new SsyxException(ResultCodeEnum.DATA_ERROR);
        }

        //2 遍历skuStockLockVoList得到每个商品，验证库存并锁定库存，具备原子性
        skuStockLockVoList.stream().forEach(skuStockLockVo -> {
            this.checkLock(skuStockLockVo);
        });

        //3 只要有一个商品锁定失败，所有锁定成功的商品都解锁
        boolean flag = skuStockLockVoList.stream()
                .anyMatch(skuStockLockVo -> !skuStockLockVo.getIsLock());
        if (flag) {
            //所有锁定成功的商品都解锁
            skuStockLockVoList.stream().filter(SkuStockLockVo::getIsLock)
                    .forEach(skuStockLockVo -> {
                        baseMapper.unlockStock(skuStockLockVo.getSkuId(),
                                skuStockLockVo.getSkuNum());
                    });
            //返回失败的状态
            return false;
        }

        //4 如果所有商品都锁定成功了，redis缓存相关数据，为了方便后面解锁和减库存
        redisTemplate.opsForValue()
                .set(RedisConst.SROCK_INFO + orderNo, skuStockLockVoList);
        return true;
    }