Grain Mall Notes + Stepping on the Pit (21) - Submit an order. Atomic Verification Token + Locked Inventory

Table of contents

1. Environment preparation

1.1. Business process

1.2. Controller layer writes the order function interface

1.3. Model class for order submission

1.4. The front-end page confirm.html provides data

2. Submit the complete code of the order business

3. Atomic verification of tokens: the comparison and deletion of tokens ensures atomicity

4. Initialize the new order, including order, order item and other information

4.1. Extract order and create transmission class

4.2、service

4.3. Create an order

4.3.1. Remote call warehouse service, interface to calculate freight and detailed address

4.3.2, package freight model class

4.3.3. Create order service

4.4. Construct line item data

4.4.1. Build order item data service

4.4.2. [Commodity Module] Query spu information through skuId

4.4.3. Order service remotely calls commodity service

4.4.4. Extract product information vo

4.5. Calculate the price

5. Lock inventory

5.1. Save order data and lock inventory

5.1.1, service saves order data and locks inventory

5.1.2, [Public Module] No inventory exception class

5.2. [Warehouse Module] Lock Inventory

5.2.1. Order service calls warehouse service remotely

5.2.2, lock inventory controller

5.2.3. vo class that locks inventory

5.2.4. Lock the inventory service of the specified order

5.2.5, dao, according to sku_id query in the warehouse with inventory

5.2.6. [Public Module] Add inventory-related error codes to the error code enumeration class

6. Modification of the front-end page

7. Submit the complete code of the order

7.1. Write Controller layer interface

7.2, Service layer code

7.2.1. Submit order business

7.2.2. Methods of creating orders, constructing orders, calculating prices, etc.

---

1. Environment preparation

1.1. Business process

1.2. Controller layer writes the order function interface

com.atguigu.gulimall.order.web The OrderWebController class under the order service  path, the code is as follows

/**
 * 下单功能
 * @param vo
 * @return
 */
@PostMapping("/submitOrder")
public String submitOrder(OrderSubmitVo vo, Model model, RedirectAttributes redirectAttributes){
    // 1、创建订单、验令牌、验价格、验库存
    try {
        SubmitOrderResponseVo responseVo = orderService.submitOrder(vo);
        if (responseVo.getCode() == 0) {
            // 下单成功来到支付选择页
            model.addAttribute("submitOrderResp",responseVo);
            return "pay";
        } else {
            // 下单失败回到订单确认页重新确认订单信息
            String msg = "下单失败: ";
            switch ( responseVo.getCode()){
                case 1: msg+="订单信息过期，请刷新再次提交";break;
                case 2: msg+="订单商品价格发生变化，请确认后再次提交";break;
                case 3: msg+="商品库存不足";break;
            }
            redirectAttributes.addAttribute("msg",msg);
            return "redirect:http://order.gulimall.cn/toTrade";
        }
    } catch (Exception e){
        if (e instanceof NoStockException) {
            String message = e.getMessage();
            redirectAttributes.addFlashAttribute("msg", message);
        }
        return "redirect:http://order.gulimall.cn/toTrade";
    }

}

1.3. Model class for order submission

---

Add the "com.atguigu.gulimall.order.vo.OrderSubmitVo" class to the page submission data, the code is as follows:

@Data
@ToString
public class OrderSubmitVo {
    /**
     * 收货地址Id
     */
    private Long addrId;
    /**
     * 支付方式
     */
    private Integer payType;
    // 无需提交需要购买的商品，去购物车再获取一遍
    // 优惠发票
    /**
     * 防重令牌
     */
    private String orderToken;
    /**
     * 应付价格，验价
     */
    private BigDecimal payPrice;
    /**
     * 订单备注
     */
    private String note;

    /**
     * 用户相关信息，直接去Session取出登录的用户
     */
}

1.4. The front-end page confirm.html provides data

<form action="http://order.gulimall.cn/submitOrder" method="post">
   <input id="addrIdInput" type="hidden" name="addrId">
   <input id="payPriceInput" type="hidden" name="payPrice">
   <input type="hidden" name="orderToken" th:value="${orderConfirmData.orderToken}">
   <button class="tijiao" type="submit">提交订单</button>
</form>

function getFare(addrId) {
   // 给表单回填的地址
   $("#addrIdInput").val(addrId);
   $.get("http://gulimall.cn/api/ware/wareinfo/fare?addrId="+addrId,function (resp) {
      console.log(resp);
      $("#fareEle").text(resp.data.fare);
      var total = [[${orderConfirmData.total}]]
      // 设置运费信息
      var pryPrice = total*1 + resp.data.fare*1;
      $("#payPriceEle").text(pryPrice);
      $("#payPriceInput").val(pryPrice);
      // 设置收货人信息
      $("#reciveAddressEle").text(resp.data.address.province+" " + resp.data.address.region+ "" + resp.data.address.detailAddress);
      $("#reveiverEle").text(resp.data.address.name);
   })
}

2. Submit the complete code of the order business

   /**
     * 提交订单
     * @param vo
     * @return
     */
    // @Transactional(isolation = Isolation.READ_COMMITTED) 设置事务的隔离级别
    // @Transactional(propagation = Propagation.REQUIRED)   设置事务的传播级别
    @Transactional(rollbackFor = Exception.class)
    // @GlobalTransactional(rollbackFor = Exception.class)
    @Override
    public SubmitOrderResponseVo submitOrder(OrderSubmitVo vo) {

        confirmVoThreadLocal.set(vo);

        SubmitOrderResponseVo responseVo = new SubmitOrderResponseVo();
        //去创建、下订单、验令牌、验价格、锁定库存...

        //1.从拦截器中获取当前用户登录的信息
        MemberResponseVo memberResponseVo = LoginUserInterceptor.loginUser.get();
        responseVo.setCode(0);

        //2、验证令牌是否合法【令牌的对比和删除必须保证原子性】
        String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
        String orderToken = vo.getOrderToken();

        //通过lure脚本原子验证令牌和删除令牌
        Long result = redisTemplate.execute(new DefaultRedisScript<Long>(script, Long.class),
                Arrays.asList(USER_ORDER_TOKEN_PREFIX + memberResponseVo.getId()),
                orderToken);

        if (result == 0L) {
            //令牌验证失败
            responseVo.setCode(1);
            return responseVo;
        } else {
            //令牌验证成功
            //1、创建订单、订单项等信息
            OrderCreateTo order = createOrder();

            //2、验证价格
            BigDecimal payAmount = order.getOrder().getPayAmount();
            BigDecimal payPrice = vo.getPayPrice();

            if (Math.abs(payAmount.subtract(payPrice).doubleValue()) < 0.01) {
                //金额对比
                //TODO 3、保存订单
                saveOrder(order);

                //4、库存锁定,只要有异常，回滚订单数据
                //订单号、所有订单项信息(skuId,skuNum,skuName)
                WareSkuLockVo lockVo = new WareSkuLockVo();
                lockVo.setOrderSn(order.getOrder().getOrderSn());

                //获取出要锁定的商品数据信息
                List<OrderItemVo> orderItemVos = order.getOrderItems().stream().map((item) -> {
                    OrderItemVo orderItemVo = new OrderItemVo();
                    orderItemVo.setSkuId(item.getSkuId());
                    orderItemVo.setCount(item.getSkuQuantity());
                    orderItemVo.setTitle(item.getSkuName());
                    return orderItemVo;
                }).collect(Collectors.toList());
                lockVo.setLocks(orderItemVos);

                //TODO 调用远程锁定库存的方法
                //出现的问题：扣减库存成功了，但是由于网络原因超时，出现异常，导致订单事务回滚，库存事务不回滚(解决方案：seata)
                //为了保证高并发，不推荐使用seata，因为是加锁，并行化，提升不了效率,可以发消息给库存服务
                R r = wmsFeignService.orderLockStock(lockVo);
                if (r.getCode() == 0) {
                    //锁定成功
                    responseVo.setOrder(order.getOrder());
                    // int i = 10/0;

                    //TODO 订单创建成功，发送消息给MQ
                    rabbitTemplate.convertAndSend("order-event-exchange","order.create.order",order.getOrder());

                    //删除购物车里的数据
                    redisTemplate.delete(CART_PREFIX+memberResponseVo.getId());
                    return responseVo;
                } else {
                    //锁定失败
                    String msg = (String) r.get("msg");
                    throw new NoStockException(msg);
                    // responseVo.setCode(3);
                    // return responseVo;
                }

            } else {
                responseVo.setCode(2);
                return responseVo;
            }
        }
    }

3. Atomic verification of tokens: the comparison and deletion of tokens ensures atomicity

---

Problem: There is a network delay, and the token obtained from Redis is submitted at the same time, resulting in repeated submissions

Solution: The comparison and deletion of tokens must ensure atomicity

1), package and submit order data

package com.atguigu.gulimall.order.vo;

@Data
public class SubmitOrderResponseVo {
    private OrderEntity order;
    private Integer code;   //0成功,错误状态码
}

2), Modify the SubmitOrderResponseVo class to write the verification token operation

/**
 * 下单操作：验令牌、创建订单、验价格、验库存
 * @param vo
 * @return
 */
@Override
public SubmitOrderResponseVo submitOrder(OrderSubmitVo vo) {
    SubmitOrderResponseVo response = new SubmitOrderResponseVo();

    // 从拦截器中拿到当前的用户
    MemberRespVo memberRespVo = LoginUserInterceptor.loginUser.get();
    // 1、验证令牌【令牌的对比和删除必须保证原子性】,通过使用脚本来完成(0：令牌校验失败; 1: 删除成功)
    String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
    String orderToken = vo.getOrderToken();
    // 原子验证令牌和删除令牌
    Long result = redisTemplate.execute(new DefaultRedisScript<Long>(script, Long.class), Arrays.asList(),
            OrderConstant.USER_ORDER_TOKEN_PREFIX + memberRespVo.getId(), orderToken);
    if (result == 0L) {
        // 令牌验证失败
        response.setCode(1);
        return response;
    } else {
        // 令牌验证成功
        return response;
    }
}

4. Initialize the new order, including order, order item and other information

4.1. Extract order and create transmission class

@Data
public class OrderCreateTo {

    private OrderEntity order;

    private List<OrderItemEntity> orderItems;

    /** 订单计算的应付价格 **/
    private BigDecimal payPrice;

    /** 运费 **/
    private BigDecimal fare;

}

4.2、service

com.atguigu.gulimall.order.service.impl The OrderServiceImpl class under the path in the gulimall-order service 

/**
 * 创建订单、订单项等信息
 * @return
 */
private OrderCreateTo createOrder(){
    OrderCreateTo createTo = new OrderCreateTo();
    // 1、生成一个订单号。IdWorker.getTimeId()是Mybatis提供的生成订单号方法，ID=Time+Id
    String orderSn = IdWorker.getTimeId();
    // 2、构建一个订单
    OrderEntity orderEntity = buildOrder(orderSn);
    // 3、获取到所有的订单项
    List<OrderItemEntity> itemEntities = buildOrderItems(orderSn);
    // 4、计算价格、积分等相关信息
    computePrice(orderEntity,itemEntities);

    createTo.setOrder(orderEntity);
    createTo.setOrderItems(itemEntities);
    return createTo;
}

4.3. Create an order

4.3.1. Remote call warehouse service, interface to calculate freight and detailed address

package com.atguigu.gulimall.order.feign;

@FeignClient("gulimall-ware")
public interface WareFeignService {

    @PostMapping("/ware/waresku/hasstock")
    R getSkusHasStock(@RequestBody List<Long> skuIds);

    /**
     * 计算运费和详细地址
     * @param addrId
     * @return
     */
    @GetMapping("/ware/wareinfo/fare")
    R getFare(@RequestParam("addrId") Long addrId);
}

4.3.2, package freight model class

package com.atguigu.gulimall.order.vo;

@Data
public class FareVo {
    private MemberAddressVo address;
    private BigDecimal fare;
}

4.3.3. Create order service

/**
 * 构建订单
 * @param orderSn
 * @return
 */
private OrderEntity buildOrder(String orderSn) {
    MemberRespVo respVp = LoginUserInterceptor.loginUser.get();
    OrderEntity entity = new OrderEntity();
    entity.setOrderSn(orderSn);
    entity.setMemberId(respVp.getId());

    OrderSubmitVo orderSubmitVo = confirmVoThreadLocal.get();
    // 1、获取运费 和 收货信息
    R fare = wareFeignService.getFare(orderSubmitVo.getAddrId());
    FareVo fareResp = fare.getData(new TypeReference<FareVo>() {
    });
    // 2、设置运费
    entity.setFreightAmount(fareResp.getFare());
    // 3、设置收货人信息
    entity.setReceiverPostCode(fareResp.getAddress().getPostCode());
    entity.setReceiverProvince(fareResp.getAddress().getProvince());
    entity.setReceiverRegion(fareResp.getAddress().getRegion());
    entity.setReceiverCity(fareResp.getAddress().getCity());
    entity.setReceiverDetailAddress(fareResp.getAddress().getDetailAddress());
    entity.setReceiverName(fareResp.getAddress().getName());
    entity.setReceiverPhone(fareResp.getAddress().getPhone());
    // 4、设置订单的相关状态信息
    entity.setStatus(OrderStatusEnum.CREATE_NEW.getCode());
    // 5、默认取消信息
    entity.setAutoConfirmDay(7);
    return entity;
}

4.4. Construct line item data

4.4.1. Build order item data service

OrderServiceImpl class

/**
 * 构建所有订单项数据
 * @return
 */
private  List<OrderItemEntity> buildOrderItems(String orderSn) {
    // 最后确定每个购物项的价格
    List<OrderItemVo> currentUserCartItems = cartFeignService.getCurrentUserCartItems();
    if (currentUserCartItems != null && currentUserCartItems.size()>0){
        List<OrderItemEntity> itemEntities = currentUserCartItems.stream().map(cartItem -> {
            OrderItemEntity itemEntity = buildOrderItem(cartItem);
            itemEntity.setOrderSn(orderSn);
            return itemEntity;
        }).collect(Collectors.toList());
        return itemEntities;
    }
    return null;
}

/**
 * 构建某一个订单项
 * @param cartItem
 * @return
 */
private OrderItemEntity buildOrderItem(OrderItemVo cartItem) {
    OrderItemEntity itemEntity = new OrderItemEntity();
    // 1、订单信息：订单号 v
    // 2、商品的spu信息
    Long skuId = cartItem.getSkuId();
    R r = productFeignService.getSpuInfoBySkuId(skuId);
    SpuInfoVo data = r.getData(new TypeReference<SpuInfoVo>() {
    });
    itemEntity.setSpuId(data.getId());
    itemEntity.setSpuBrand(data.getBrandId().toString());
    itemEntity.setSpuName(data.getSpuName());
    itemEntity.setCategoryId(data.getCatalogId());
    // 3、商品的sku信息  v
    itemEntity.setSkuId(cartItem.getSkuId());
    itemEntity.setSkuName(cartItem.getTitle());
    itemEntity.setSkuPic(cartItem.getImage());
    itemEntity.setSkuPrice(cartItem.getPrice());
    itemEntity.setSkuQuantity(cartItem.getCount());
    itemEntity.setSkuAttrsVals(StringUtils.collectionToDelimitedString(cartItem.getSkuAttr(),";"));
    // 4、优惠信息【不做】
    // 5、积分信息
    itemEntity.setGiftGrowth(cartItem.getPrice().multiply(new BigDecimal(cartItem.getCount().toString())).intValue());
    itemEntity.setGiftIntegration(cartItem.getPrice().multiply(new BigDecimal(cartItem.getCount().toString())).intValue());
    // 6、订单项的价格信息
    itemEntity.setPromotionAmount(new BigDecimal("0"));
    itemEntity.setCouponAmount(new BigDecimal("0"));
    itemEntity.setIntegrationAmount(new BigDecimal("0"));
    // 当前订单项的实际金额 总额-各种优惠
    BigDecimal orign = itemEntity.getSkuPrice().multiply(new BigDecimal(itemEntity.getSkuQuantity().toString()));
    BigDecimal subtract = orign.subtract(itemEntity.getCouponAmount()).
            subtract(itemEntity.getCouponAmount()).
            subtract(itemEntity.getIntegrationAmount());
    itemEntity.setRealAmount(subtract);
    return itemEntity;
}

4.4.2. [Commodity Module] Query spu information through skuId

package com.atguigu.gulimall.product.app;

@RestController
@RequestMapping("product/spuinfo")
public class SpuInfoController {
    @Autowired
    private SpuInfoService spuInfoService;


    /**
     * 查询指定sku的spu信息
     * @param skuId
     * @return
     */
    @GetMapping("/skuId/{id}")
    public R getSpuInfoBySkuId(@PathVariable("id") Long skuId) {
        SpuInfoEntity entity = spuInfoService.getSpuInfoBySkuId(skuId);
        return R.ok().setData(entity);
    }

package com.atguigu.gulimall.product.service.impl;

@Override
public SpuInfoEntity getSpuInfoBySkuId(Long skuId) {
    SkuInfoEntity byId = skuInfoService.getById(skuId);
    Long spuId = byId.getSpuId();
    SpuInfoEntity spuInfoEntity = getById(spuId);
    return spuInfoEntity;
}

4.4.3. Order service remotely calls commodity service

package com.atguigu.gulimall.order.feign;
@FeignClient("gulimall-product")
public interface ProductFeignService {

    @GetMapping("/product/spuinfo/skuId/{id}")
    R getSpuInfoBySkuId(@PathVariable("id") Long skuId);
}

4.4.4. Extract product information vo

package com.atguigu.gulimall.order.vo;

@Data
public class SpuInfoVo {
    /**
     * 商品id
     */
    @TableId
    private Long id;
    /**
     * 商品名称
     */
    private String spuName;
    /**
     * 商品描述
     */
    private String spuDescription;
    /**
     * 所属分类id
     */
    private Long catalogId;
    /**
     * 品牌id
     */
    private Long brandId;
    /**
     *
     */
    private BigDecimal weight;
    /**
     * 上架状态[0 - 新建，1 - 上架，2-下架]
     */
    private Integer publishStatus;
    /**
     *
     */
    private Date createTime;
    /**
     *
     */
    private Date updateTime;
}

4.5. Calculate the price

/**
 * 计算价格
 * @param orderEntity
 * @param itemEntities
 */
private void computePrice(OrderEntity orderEntity, List<OrderItemEntity> itemEntities) {
    BigDecimal total = new BigDecimal("0.0");
    BigDecimal coupon = new BigDecimal("0.0");
    BigDecimal integration = new BigDecimal("0.0");
    BigDecimal promotion = new BigDecimal("0.0");
    BigDecimal gift = new BigDecimal("0.0");
    BigDecimal growth = new BigDecimal("0.0");
    // 1、订单的总额，叠加每一个订单项的总额信息
    for (OrderItemEntity entity : itemEntities) {
        total = total.add(entity.getRealAmount());
        coupon = coupon.add(entity.getCouponAmount());
        integration = integration.add(entity.getIntegrationAmount());
        promotion = promotion.add(entity.getPromotionAmount());
        gift = gift.add(new BigDecimal(entity.getGiftIntegration()));
        growth = growth.add(new BigDecimal(entity.getGiftGrowth()));
    }
    // 订单总额
    orderEntity.setTotalAmount(total);
    // 应付总额
    orderEntity.setPayAmount(total.add(orderEntity.getFreightAmount()));
    orderEntity.setCouponAmount(coupon);
    orderEntity.setIntegrationAmount(integration);
    orderEntity.setPromotionAmount(promotion);
    // 设置积分等信息
    orderEntity.setIntegration(gift.intValue());
    orderEntity.setGrowth(growth.intValue());
    orderEntity.setDeleteStatus(0);//0 未删除
}

5. Lock inventory

5.1. Save order data and lock inventory

5.1.1, service saves order data and locks inventory

/**
 * 下单操作：验令牌、创建订单、验价格、验库存
 * @param vo
 * @return
 */
@Transactional
@Override
public SubmitOrderResponseVo submitOrder(OrderSubmitVo vo) {
    // 在当前线程共享 OrderSubmitVo
    confirmVoThreadLocal.set(vo);
    SubmitOrderResponseVo response = new SubmitOrderResponseVo();
    // 从拦截器中拿到当前的用户
    MemberRespVo memberRespVo = LoginUserInterceptor.loginUser.get();
    response.setCode(0);

    // 1、验证令牌【令牌的对比和删除必须保证原子性】,通过使用脚本来完成(0：令牌校验失败; 1: 删除成功)
    String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
    String orderToken = vo.getOrderToken();
    // 原子验证令牌和删除令牌
    Long result = redisTemplate.execute(new DefaultRedisScript<>(script, Long.class),
            Arrays.asList(OrderConstant.USER_ORDER_TOKEN_PREFIX + memberRespVo.getId()), orderToken);
    if (result == 0L) {
        // 令牌验证失败
        response.setCode(1);
        return response;
    } else {
        // 令牌验证成功
        // 2、创建订单、订单项等信息
        OrderCreateTo order = createOrder();
        // 3、验价
        BigDecimal payAmount = order.getOrder().getPayAmount();
        BigDecimal payPrice = vo.getPayPrice();
        if (Math.abs(payAmount.subtract(payPrice).doubleValue())<0.01){
            // 金额对比成功
            // 4、保存订单;
            saveOrder(order);
            // 5、库存锁定，只要有异常回滚订单数据
            // 订单号，所有订单项(skuId,skuName,num)
            WareSkuLockVo lockVo = new WareSkuLockVo();
            lockVo.setOrderSn(order.getOrder().getOrderSn());
            List<OrderItemVo> locks = order.getOrderItems().stream().map(item -> {
                OrderItemVo itemVo = new OrderItemVo();
                itemVo.setSkuId(item.getSkuId());
                itemVo.setCount(item.getSkuQuantity());
                itemVo.setTitle(item.getSkuName());
                return itemVo;
            }).collect(Collectors.toList());
            lockVo.setLocks(locks);
            // TODO 远程锁库存
            R r = wareFeignService.orderLockStock(lockVo);
            if (r.getCode() == 0) {
                // 锁成功了
                response.setOrder(order.getOrder());
                return response;
            }else {
                // 锁定失败
                throw new NoStockException((String) r.get("msg"));
            }

        } else {
            // 金额对比失败
            response.setCode(2);
            return response;
        }
    }
}

5.1.2, [Public Module] No inventory exception class

package com.atguigu.common.exception;

public class NoStockException extends RuntimeException{
    private Long skuId;

    public NoStockException(Long skuId){
        super("商品id:"+skuId+"；没有足够的库存了！");
    }

    public NoStockException(String message) {
        super(message);
    }

    @Override
    public String getMessage() {
        return super.getMessage();
    }

    public Long getSkuId() {
        return skuId;
    }

    public void setSkuId(Long skuId) {
        this.skuId = skuId;
    }

}

5.2. [Warehouse Module] Lock Inventory

5.2.1. Order service calls warehouse service remotely

package com.atguigu.gulimall.order.feign;

@FeignClient("gulimall-ware")
public interface WareFeignService {
        //....

    /**
     * 锁定指定订单的库存
     * @param vo
     * @return
     */
    @PostMapping("/ware/waresku/lock/order")
    R orderLockStock(@RequestBody WareSkuLockVo vo);
}

5.2.2, lock inventory controller

package com.atguigu.gulimall.ware.controller;

@RestController
@RequestMapping("ware/waresku")
public class WareSkuController {
    @Autowired
    private WareSkuService wareSkuService;

    /**
     * 锁定订单项库存
     * @param vo
     * @return
     */
    @PostMapping("/lock/order")
    public R orderLockStock(@RequestBody WareSkuLockVo vo){
        try {
            Boolean stock = wareSkuService.orderLockStock(vo);
            return R.ok();
        } catch (NoStockException e){
            return R.error(BizCodeEnume.NO_STOCK_EXCEPTION.getCode(),BizCodeEnume.NO_STOCK_EXCEPTION.getMsg());
        }
    }
  //....
}

5.2.3. vo class that locks inventory

/**
 * @Description: 锁定库存的vo
 **/

@Data
public class WareSkuLockVo {

    private String orderSn;

    /** 需要锁住的所有库存信息 **/
    private List<OrderItemVo> locks;



}

5.2.4. Lock the inventory service of the specified order

package com.atguigu.gulimall.ware.service.impl;

@Service("wareSkuService")
public class WareSkuServiceImpl extends ServiceImpl<WareSkuDao, WareSkuEntity> implements WareSkuService {

    @Autowired
    WareSkuDao wareSkuDao;

    @Autowired
    ProductFeignService productFeignService;
        //......

    /**
     * 锁定指定订单的库存
     * @param vo
     * @return
     * (rollbackFor = NoStockException.class)
     * 默认只要是运行时异常都会回滚
     */
    @Transactional
    @Override
    public Boolean orderLockStock(WareSkuLockVo vo) {
        // 1、每个商品在哪个库存里有库存
        List<OrderItemVo> locks = vo.getLocks();
        List<SkuWareHashStock> collect = locks.stream().map(item -> {
            SkuWareHashStock stock = new SkuWareHashStock();
            Long skuId = item.getSkuId();
            stock.setSkuId(skuId);
            stock.setNum(item.getCount());
            // 查询这个商品在哪里有库存
            List<Long> wareIds = wareSkuDao.listWareIdHashSkuStock(skuId);
            stock.setWareId(wareIds);
            return stock;
        }).collect(Collectors.toList());

        // 2、锁定库存
        for (SkuWareHashStock hashStock : collect) {
            Boolean skuStocked = false;
            Long skuId = hashStock.getSkuId();
            List<Long> wareIds = hashStock.getWareId();
            if (wareIds == null || wareIds.size()==0){
                // 没有任何仓库有这个商品的库存
                throw new NoStockException(skuId);
            }
            for (Long wareId : wareIds) {
                // 成功就返回1，否则就返回0
                Long count = wareSkuDao.lockSkuStock(skuId,wareId,hashStock.getNum());
                if (count == 1){
                    skuStocked = true;
                    break;
                } else {
                    // 当前仓库锁失败，重试下一个仓库

                }
            }
            if (skuStocked == false){
                // 当前商品所有仓库都没有锁住，其他商品也不需要锁了，直接返回没有库存了
                throw new NoStockException(skuId);
            }
        }

        // 3、运行到这，全部都是锁定成功的
        return true;
    }
    @Data
    class SkuWareHashStock{
        private Long skuId;     // skuid
        private Integer num;    // 锁定件数
        private List<Long> wareId;  // 锁定仓库id
    }

}

5.2.5, dao, according to sku_id query in the warehouse with inventory

com.atguigu.gulimall.ware.daoThe WareSkuDao class under the path in the gulimall-ware service :

package com.atguigu.gulimall.ware.dao;

@Mapper
public interface WareSkuDao extends BaseMapper<WareSkuEntity> {

    /**
     * 通过skuId查询在哪个仓库有库存
     * @param skuId
     * @return  仓库的编号
     */
    List<Long> listWareIdHashSkuStock(@Param("skuId") Long skuId);

    /**
     * 锁库存
     * @param skuId
     * @param wareId
     * @param num
     * @return
     */
    Long lockSkuStock(@Param("skuId") Long skuId, @Param("wareId") Long wareId, @Param("num") Integer num);

}

gulimall-ware/src/main/resources/mapper/wareWareSkuDao.xml under the path in the gulimall-ware service :

<update id="addStock">
    UPDATE `wms_ware_sku` SET stock=stock+#{skuNum} WHERE sku_id=#{skuId} AND ware_id=#{wareId}
</update>

<select id="listWareIdHashSkuStock" resultType="java.lang.Long">
    SELECT ware_id FROM wms_ware_sku WHERE sku_id=#{skuId} and stock-stock_locked>0;
</select>

5.2.6. [Public Module] Add inventory-related error codes to the error code enumeration class

Add inventory error codes and information in the error code and error message definition class BizCodeEnume enumeration class

com.atguigu.common.exceptionBizCodeEnume under the path in the gulimall-common service :

Error codes starting with 21: Inventory

package com.atguigu.common.exception;

public enum BizCodeEnume {
    UNKNOW_EXCEPTION(10000,"系统未知异常"),
    VAILD_EXCEPTION(10001,"参数格式校验失败"),
    SMS_CODE_EXCEPTION(10002,"验证码获取频率太高，稍后再试"),
    PRODUCT_UP_EXCEPTION(11000,"商品上架异常"),
    USER_EXIST_EXCEPTION(15001,"用户名已存在"),
    PHONE_EXIST_EXCEPTION(15002,"手机号已被注册"),
    NO_STOCK_EXCEPTION(21000,"商品库存不足"),
    LOGINACCT_PASSWORD_INVAILD_EXCEPTION(15003,"账号或密码错误");

    private int code;
    private String msg;
    BizCodeEnume(int code,String msg){
        this.code = code;
        this.msg = msg;
    }

    public int getCode() {
        return code;
    }

    public String getMsg() {
        return msg;
    }
}

6. Modification of the front-end page

---

The order is submitted successfully, jump to the payment page pay.html

<div class="Jdbox_BuySuc">
  <dl>
    <dt><img src="/static/order/pay/img/saoyisao.png" alt=""></dt>
    <dd>
      <span>订单提交成功，请尽快付款！订单号：[[${submitOrderResp.order.orderSn}]]</span>
      <span>应付金额<font>[[${#numbers.formatDecimal(submitOrderResp.order.payAmount,1,2)}]]</font>元</span>
    </dd>
    <dd>
      <span>推荐使用</span>
      <span>扫码支付请您在<font>24小时</font>内完成支付，否则订单会被自动取消(库存紧订单请参见详情页时限)</span>
      <span>订单详细</span>
    </dd>
  </dl>
</div>

The order submission failed, redirect the item to confirm.html and echo the failure reason

---

<p class="p1">填写并核对订单信息 <span style="color: red" th:value="${msg!=null}" th:text="${msg}"></span></p>

7. Submit the complete code of the order

7.1. Write Controller layer interface

/**
 * 下单功能
 * @param vo
 * @return
 */
@PostMapping("/submitOrder")
public String submitOrder(OrderSubmitVo vo, Model model, RedirectAttributes redirectAttributes){
    // 1、创建订单、验令牌、验价格、验库存
    try {
        SubmitOrderResponseVo responseVo = orderService.submitOrder(vo);
        if (responseVo.getCode() == 0) {
            // 下单成功来到支付选择页
            model.addAttribute("submitOrderResp",responseVo);
            return "pay";
        } else {
            // 下单失败回到订单确认页重新确认订单信息
            String msg = "下单失败: ";
            switch ( responseVo.getCode()){
                case 1: msg+="订单信息过期，请刷新再次提交";break;
                case 2: msg+="订单商品价格发生变化，请确认后再次提交";break;
                case 3: msg+="商品库存不足";break;
            }
            redirectAttributes.addAttribute("msg",msg);
            return "redirect:http://order.gulimall.cn/toTrade";
        }
    } catch (Exception e){
        if (e instanceof NoStockException) {
            String message = e.getMessage();
            redirectAttributes.addFlashAttribute("msg", message);
        }
        return "redirect:http://order.gulimall.cn/toTrade";
    }

}

7.2, Service layer code

7.2.1. Submit order business

   /**
     * 提交订单
     * @param vo
     * @return
     */
    // @Transactional(isolation = Isolation.READ_COMMITTED) 设置事务的隔离级别
    // @Transactional(propagation = Propagation.REQUIRED)   设置事务的传播级别
    @Transactional(rollbackFor = Exception.class)
    // @GlobalTransactional(rollbackFor = Exception.class)
    @Override
    public SubmitOrderResponseVo submitOrder(OrderSubmitVo vo) {

        confirmVoThreadLocal.set(vo);

        SubmitOrderResponseVo responseVo = new SubmitOrderResponseVo();
        //去创建、下订单、验令牌、验价格、锁定库存...

        //1.从拦截器中获取当前用户登录的信息
        MemberResponseVo memberResponseVo = LoginUserInterceptor.loginUser.get();
        responseVo.setCode(0);

        //2、验证令牌是否合法【令牌的对比和删除必须保证原子性】
        String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
        String orderToken = vo.getOrderToken();

        //通过lure脚本原子验证令牌和删除令牌
        Long result = redisTemplate.execute(new DefaultRedisScript<Long>(script, Long.class),
                Arrays.asList(USER_ORDER_TOKEN_PREFIX + memberResponseVo.getId()),
                orderToken);

        if (result == 0L) {
            //令牌验证失败
            responseVo.setCode(1);
            return responseVo;
        } else {
            //令牌验证成功
            //1、创建订单、订单项等信息
            OrderCreateTo order = createOrder();

            //2、验证价格
            BigDecimal payAmount = order.getOrder().getPayAmount();
            BigDecimal payPrice = vo.getPayPrice();

            if (Math.abs(payAmount.subtract(payPrice).doubleValue()) < 0.01) {
                //金额对比
                //TODO 3、保存订单
                saveOrder(order);

                //4、库存锁定,只要有异常，回滚订单数据
                //订单号、所有订单项信息(skuId,skuNum,skuName)
                WareSkuLockVo lockVo = new WareSkuLockVo();
                lockVo.setOrderSn(order.getOrder().getOrderSn());

                //获取出要锁定的商品数据信息
                List<OrderItemVo> orderItemVos = order.getOrderItems().stream().map((item) -> {
                    OrderItemVo orderItemVo = new OrderItemVo();
                    orderItemVo.setSkuId(item.getSkuId());
                    orderItemVo.setCount(item.getSkuQuantity());
                    orderItemVo.setTitle(item.getSkuName());
                    return orderItemVo;
                }).collect(Collectors.toList());
                lockVo.setLocks(orderItemVos);

                //TODO 调用远程锁定库存的方法
                //出现的问题：扣减库存成功了，但是由于网络原因超时，出现异常，导致订单事务回滚，库存事务不回滚(解决方案：seata)
                //为了保证高并发，不推荐使用seata，因为是加锁，并行化，提升不了效率,可以发消息给库存服务
                R r = wmsFeignService.orderLockStock(lockVo);
                if (r.getCode() == 0) {
                    //锁定成功
                    responseVo.setOrder(order.getOrder());
                    // int i = 10/0;

                    //TODO 订单创建成功，发送消息给MQ
                    rabbitTemplate.convertAndSend("order-event-exchange","order.create.order",order.getOrder());

                    //删除购物车里的数据
                    redisTemplate.delete(CART_PREFIX+memberResponseVo.getId());
                    return responseVo;
                } else {
                    //锁定失败
                    String msg = (String) r.get("msg");
                    throw new NoStockException(msg);
                    // responseVo.setCode(3);
                    // return responseVo;
                }

            } else {
                responseVo.setCode(2);
                return responseVo;
            }
        }
    }

7.2.2. Methods of creating orders, constructing orders, calculating prices, etc.

    /**
     * 创建订单、订单项等信息
     * @return
     */
    private OrderCreateTo createOrder(){
        OrderCreateTo createTo = new OrderCreateTo();
        // 1、生成一个订单号
        String orderSn = IdWorker.getTimeId();
        // 2、构建一个订单
        OrderEntity orderEntity = buildOrder(orderSn);
        // 3、获取到所有的订单项
        List<OrderItemEntity> itemEntities = buildOrderItems(orderSn);
        // 4、计算价格、积分等相关信息
        computePrice(orderEntity,itemEntities);

        createTo.setOrder(orderEntity);
        createTo.setOrderItems(itemEntities);
        return createTo;
    }



    /**
     * 构建订单
     * @param orderSn
     * @return
     */
    private OrderEntity buildOrder(String orderSn) {
        MemberRespVo respVp = LoginUserInterceptor.loginUser.get();
        OrderEntity entity = new OrderEntity();
        entity.setOrderSn(orderSn);
        entity.setMemberId(respVp.getId());

        OrderSubmitVo orderSubmitVo = confirmVoThreadLocal.get();
        // 1、获取运费 和 收货信息
        R fare = wareFeignService.getFare(orderSubmitVo.getAddrId());
        FareVo fareResp = fare.getData(new TypeReference<FareVo>() {
        });
        // 2、设置运费
        entity.setFreightAmount(fareResp.getFare());
        // 3、设置收货人信息
        entity.setReceiverPostCode(fareResp.getAddress().getPostCode());
        entity.setReceiverProvince(fareResp.getAddress().getProvince());
        entity.setReceiverRegion(fareResp.getAddress().getRegion());
        entity.setReceiverCity(fareResp.getAddress().getCity());
        entity.setReceiverDetailAddress(fareResp.getAddress().getDetailAddress());
        entity.setReceiverName(fareResp.getAddress().getName());
        entity.setReceiverPhone(fareResp.getAddress().getPhone());
        // 4、设置订单的相关状态信息
        entity.setStatus(OrderStatusEnum.CREATE_NEW.getCode());
        // 5、默认取消信息
        entity.setAutoConfirmDay(7);
        return entity;
    }

    /**
     * 构建所有订单项数据
     * @return
     */
    private  List<OrderItemEntity> buildOrderItems(String orderSn) {
        // 最后确定每个购物项的价格
        List<OrderItemVo> currentUserCartItems = cartFeignService.getCurrentUserCartItems();
        if (currentUserCartItems != null && currentUserCartItems.size()>0){
            List<OrderItemEntity> itemEntities = currentUserCartItems.stream().map(cartItem -> {
                OrderItemEntity itemEntity = buildOrderItem(cartItem);
                itemEntity.setOrderSn(orderSn);
                return itemEntity;
            }).collect(Collectors.toList());
            return itemEntities;
        }
        return null;
    }

    /**
     * 构建某一个订单项
     * @param cartItem
     * @return
     */
    private OrderItemEntity buildOrderItem(OrderItemVo cartItem) {
        OrderItemEntity itemEntity = new OrderItemEntity();
        // 1、订单信息：订单号 v
        // 2、商品的spu信息
        Long skuId = cartItem.getSkuId();
        R r = productFeignService.getSpuInfoBySkuId(skuId);
        SpuInfoVo data = r.getData(new TypeReference<SpuInfoVo>() {
        });
        itemEntity.setSpuId(data.getId());
        itemEntity.setSpuBrand(data.getBrandId().toString());
        itemEntity.setSpuName(data.getSpuName());
        itemEntity.setCategoryId(data.getCatalogId());
        // 3、商品的sku信息  v
        itemEntity.setSkuId(cartItem.getSkuId());
        itemEntity.setSkuName(cartItem.getTitle());
        itemEntity.setSkuPic(cartItem.getImage());
        itemEntity.setSkuPrice(cartItem.getPrice());
        itemEntity.setSkuQuantity(cartItem.getCount());
        itemEntity.setSkuAttrsVals(StringUtils.collectionToDelimitedString(cartItem.getSkuAttr(),";"));
        // 4、优惠信息【不做】
        // 5、积分信息
        itemEntity.setGiftGrowth(cartItem.getPrice().multiply(new BigDecimal(cartItem.getCount().toString())).intValue());
        itemEntity.setGiftIntegration(cartItem.getPrice().multiply(new BigDecimal(cartItem.getCount().toString())).intValue());
        // 6、订单项的价格信息
        itemEntity.setPromotionAmount(new BigDecimal("0"));
        itemEntity.setCouponAmount(new BigDecimal("0"));
        itemEntity.setIntegrationAmount(new BigDecimal("0"));
        // 当前订单项的实际金额 总额-各种优惠
        BigDecimal orign = itemEntity.getSkuPrice().multiply(new BigDecimal(itemEntity.getSkuQuantity().toString()));
        BigDecimal subtract = orign.subtract(itemEntity.getCouponAmount()).
                subtract(itemEntity.getCouponAmount()).
                subtract(itemEntity.getIntegrationAmount());
        itemEntity.setRealAmount(subtract);
        return itemEntity;
    }

    /**
     * 计算价格
     * @param orderEntity
     * @param itemEntities
     */
    private void computePrice(OrderEntity orderEntity, List<OrderItemEntity> itemEntities) {
        BigDecimal total = new BigDecimal("0.0");
        BigDecimal coupon = new BigDecimal("0.0");
        BigDecimal integration = new BigDecimal("0.0");
        BigDecimal promotion = new BigDecimal("0.0");
        BigDecimal gift = new BigDecimal("0.0");
        BigDecimal growth = new BigDecimal("0.0");
        // 1、订单的总额，叠加每一个订单项的总额信息
        for (OrderItemEntity entity : itemEntities) {
            total = total.add(entity.getRealAmount());
            coupon = coupon.add(entity.getCouponAmount());
            integration = integration.add(entity.getIntegrationAmount());
            promotion = promotion.add(entity.getPromotionAmount());
            gift = gift.add(new BigDecimal(entity.getGiftIntegration()));
            growth = growth.add(new BigDecimal(entity.getGiftGrowth()));
        }
        // 订单总额
        orderEntity.setTotalAmount(total);
        // 应付总额
        orderEntity.setPayAmount(total.add(orderEntity.getFreightAmount()));
        orderEntity.setCouponAmount(coupon);
        orderEntity.setIntegrationAmount(integration);
        orderEntity.setPromotionAmount(promotion);
        }