订单的提交：

流程分析：

 订单添加接口的实现：

数据库操作：

 修改了ShoppingCartMapper:

 

 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.qfedu.fmmall.dao.ShoppingCartMapper">
  <resultMap id="BaseResultMap" type="com.qfedu.fmmall.entity.ShoppingCart">
    <result column="cart_id" jdbcType="INTEGER" property="cartId" />
    <result column="product_id" jdbcType="VARCHAR" property="productId" />
    <result column="sku_id" jdbcType="VARCHAR" property="skuId" />
    <result column="user_id" jdbcType="VARCHAR" property="userId" />
    <result column="cart_num" jdbcType="VARCHAR" property="cartNum" />
    <result column="cart_time" jdbcType="VARCHAR" property="cartTime" />
    <result column="product_price" jdbcType="DECIMAL" property="productPrice" />
    <result column="sku_props" jdbcType="VARCHAR" property="skuProps" />
  </resultMap>

  <resultMap id="ShoppingCartVOMap" type="com.qfedu.fmmall.entity.ShoppingCartVO">
    <result column="cart_id" jdbcType="INTEGER" property="cartId" />
    <result column="product_id" jdbcType="VARCHAR" property="productId" />
    <result column="sku_id" jdbcType="VARCHAR" property="skuId" />
    <result column="user_id" jdbcType="VARCHAR" property="userId" />
    <result column="cart_num" jdbcType="VARCHAR" property="cartNum" />
    <result column="cart_time" jdbcType="VARCHAR" property="cartTime" />
    <result column="product_price" jdbcType="DECIMAL" property="productPrice" />
    <result column="sku_props" jdbcType="VARCHAR" property="skuProps" />
    <result column="product_name" jdbcType="VARCHAR" property="productName" />
    <result column="url" jdbcType="VARCHAR" property="productImg" />
    <result column="original_price" jdbcType="VARCHAR" property="originalPrice" />
    <result column="sell_price" jdbcType="VARCHAR" property="sellPrice" />
    <result column="sku_name" jdbcType="VARCHAR" property="skuName" />
  </resultMap>

  <resultMap id="ShoppingCartVOMap2" type="com.qfedu.fmmall.entity.ShoppingCartVO">
    <result column="cart_id" jdbcType="INTEGER" property="cartId" />
    <result column="product_id" jdbcType="VARCHAR" property="productId" />
    <result column="sku_id" jdbcType="VARCHAR" property="skuId" />
    <result column="user_id" jdbcType="VARCHAR" property="userId" />
    <result column="cart_num" jdbcType="VARCHAR" property="cartNum" />
    <result column="cart_time" jdbcType="VARCHAR" property="cartTime" />
    <result column="product_price" jdbcType="DECIMAL" property="productPrice" />
    <result column="sku_props" jdbcType="VARCHAR" property="skuProps" />
    <result column="product_name" jdbcType="VARCHAR" property="productName" />
    <result column="url" jdbcType="VARCHAR" property="productImg" />
    <result column="original_price" jdbcType="VARCHAR" property="originalPrice" />
    <result column="sell_price" jdbcType="VARCHAR" property="sellPrice" />
    <result column="sku_name" jdbcType="VARCHAR" property="skuName" />
    <result column="stock"  property="skuStock" />
  </resultMap>

  <select id="selectShopCartByUserId" resultMap="ShoppingCartVOMap">
    select c.cart_id,
        c.product_id,
        c.sku_id,
        c.user_id,
        c.cart_num,
        c.cart_time,
        c.product_price,
        c.sku_props,
        p.product_name, i.url,
        s.original_price,s.sell_price,s.sku_name
    from shopping_cart c
    INNER JOIN product p
    INNER JOIN product_img i
    INNER JOIN product_sku s
    ON c.product_id = p.product_id
    and i.item_id = p.product_id
    and c.sku_id = s.sku_id
    where user_id = #{userId}
    and i.is_main=1
  </select>
  
  <update id="updateCartNumByCartId">
    update shopping_cart set cart_num=#{cartNum} where cart_id=#{cartId}
  </update>

  <select id="selectShopCartByCids" resultMap="ShoppingCartVOMap2">
    select c.cart_id,
    c.product_id,
    c.sku_id,
    c.user_id,
    c.cart_num,
    c.cart_time,
    c.product_price,
    c.sku_props,
    p.product_name, i.url,
    s.original_price,s.sell_price,s.sku_name,s.stock
    from shopping_cart c
    INNER JOIN product p
    INNER JOIN product_img i
    INNER JOIN product_sku s
    ON c.product_id = p.product_id
    and i.item_id = p.product_id
    and c.sku_id = s.sku_id
    where i.is_main = 1 and c.cart_id in
    <foreach collection="list" item="cid" separator="," open="(" close=")">
      #{cid}
    </foreach>
  </select>

</mapper>

保存订单：（tkMapper）

修改库存：（tkMapper）

保存商品快照：（tkMapper）

service接口：

package com.qfedu.fmmall.service;

import com.qfedu.fmmall.entity.Orders;
import com.qfedu.fmmall.vo.R;

/**
 * @Description: 订单接口
 * @Author : Jerry
 * @create : 2022-07-01 17:45
 */
public interface OrderService {

    public R addOrder(String cids, Orders order);

}

service实现类：

package com.qfedu.fmmall.service.impl;

import com.qfedu.fmmall.dao.OrderItemMapper;
import com.qfedu.fmmall.dao.OrdersMapper;
import com.qfedu.fmmall.dao.ProductSkuMapper;
import com.qfedu.fmmall.dao.ShoppingCartMapper;
import com.qfedu.fmmall.entity.OrderItem;
import com.qfedu.fmmall.entity.Orders;
import com.qfedu.fmmall.entity.ProductSku;
import com.qfedu.fmmall.entity.ShoppingCartVO;
import com.qfedu.fmmall.service.OrderService;
import com.qfedu.fmmall.vo.R;
import com.qfedu.fmmall.vo.ResStatus;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.math.BigDecimal;
import java.util.*;

/**
 * @Description:
 * @Author : Jerry
 * @create : 2022-07-01 17:46
 */
@Service
public class OrderServiceImpl implements OrderService {

    @Autowired
    private ShoppingCartMapper shoppingCartMapper;
    @Autowired
    private OrdersMapper ordersMapper;
    @Autowired
    private OrderItemMapper orderItemMapper;
    @Autowired
    private ProductSkuMapper productSkuMapper;

    /**
     * 保存订单业务
     * @param cids 在购物车列表页面选择得购物车记录的ID
     * @param order
     * @return
     */
    @Transactional
    public R addOrder(String cids, Orders order)  {
        //1.校验库存:根据cids查询当前订单中关联的购物车记录详情（包括库存）
        String[] arr = cids.split(",");
        List<Integer> cidList = new ArrayList<>();
        for (int i = 0; i<arr.length; i++){
            cidList.add(Integer.parseInt(arr[i]));
        }
        List<ShoppingCartVO> list = shoppingCartMapper.selectShopCartByCids(cidList);

        boolean f = true;
        String untitled = "";
        for (ShoppingCartVO sc: list){
            if(Integer.parseInt(sc.getCartNum())>sc.getSkuStock()){
                f = false;
            }
            //获取所有商品名称，以,分割拼接称字符串
            untitled = untitled+sc.getProductName()+",";

        }
        if(f){
            //2. 保存订单
            //收货人信息：姓名，电话，地址,商品总价格,支付方式,订单创建时间
            //订单初始状态（待支付 1）
            order.setUntitled(untitled);
            order.setCreateTime(new Date());
            order.setStatus("1");
            //生成订单编号
            String orderId = UUID.randomUUID().toString().replace("-", " ");
            order.setOrderId(orderId);
            ordersMapper.insert(order);

            //3.生成商品快照
            for(ShoppingCartVO sc:list){
                int cnum = Integer.parseInt(sc.getCartNum());
                String itemId = System.currentTimeMillis()+""+(new Random().nextInt(89999)+10000);//增大容错率
                OrderItem orderItem = new OrderItem(itemId, orderId, sc.getProductId(), sc.getProductName(), sc.getProductImg(), sc.getSkuId(), sc.getSkuName(), new BigDecimal(sc.getSellPrice())
                        , cnum, new BigDecimal(sc.getSellPrice()*cnum), new Date(), new Date(), 0);
                orderItemMapper.insert(orderItem);
            }

            //4.扣减库存：根据套餐id修改套餐库存量
            for (ShoppingCartVO sc: list){
                String skuId = sc.getSkuId();
                int newStock = sc.getSkuStock() - Integer.parseInt(sc.getCartNum());

                //updateByExampleSelective只添加修改的，其他的不变
                ProductSku productSku = new ProductSku();
                productSku.setSkuId(skuId);
                productSku.setStock(newStock);
                productSkuMapper.updateByPrimaryKeySelective(productSku);
            }

            //5.删除购物车：当购物车中得记录购买成功之后，购物车中对应做删除操作
            for(int cid:cidList){
                shoppingCartMapper.deleteByPrimaryKey(cid);
            }

            return new R(ResStatus.OK,"下单成功！",orderId);
        }else {
            //表示库存不足
            return new R(ResStatus.NO,"库存不足，下单失败！",null);
        }

    }
}

controller：

package com.qfedu.controller;

import com.qfedu.fmmall.entity.Orders;
import com.qfedu.fmmall.service.OrderService;
import com.qfedu.fmmall.vo.R;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

/**
 * @Description:
 * @Author : Jerry
 * @create : 2022-07-01 19:40
 */
@RestController
@CrossOrigin
@RequestMapping("/order")
public class OrderController {

    @Autowired
    private OrderService orderService;

    @PostMapping("/add")
    public R add(String cids, @RequestBody Orders order){
        R r = orderService.addOrder(cids, order);
        return r;
    }

}