苍穹外卖--添加购物车

购物车数据是关联用户的，在表结构中，我们需要记录，每一个用户的购物车数据是哪些
菜品列表展示出来的既有套餐，又有菜品，如果用户选择的是套餐，就保存套餐ID(setmeal_id)，如果用户选择的是菜品，就保存菜品ID(dish_id)
对同一个菜品/套餐，如果选择多份不需要添加多条记录，增加数量number即可

DTO设计

根据添加购物车接口的参数设计DTO：

在sky-pojo模块，ShoppingCartDTO.java已定义

java 复制代码

package com.sky.dto;

import lombok.Data;
import java.io.Serializable;

@Data
public class ShoppingCartDTO implements Serializable {

    private Long dishId;
    private Long setmealId;
    private String dishFlavor;

}

Controller层

根据添加购物车接口创建ShoppingCartController：

java 复制代码

package com.sky.controller.user;


import com.sky.dto.ShoppingCartDTO;
import com.sky.result.Result;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * 购物车
 */
@RestController
@RequestMapping("/user/shoppingCart")
@Slf4j
@Api(tags = "C端-购物车接口")
public class ShoppingCartController {

    @Autowired
    private ShoppingCartService shoppingCartService;

    /**
     * 添加购物车
     * @param shoppingCartDTO
     * @return
     */
    @PostMapping("/add")
    @ApiOperation("添加购物车")
    public Result<String> add(@RequestBody ShoppingCartDTO shoppingCartDTO){
        log.info("添加购物车：{}", shoppingCartDTO);
        shoppingCartService.addShoppingCart(shoppingCartDTO);//后绪步骤实现
        return Result.success();
    }
}

Service层接口

创建ShoppingCartService接口：

java 复制代码

package com.sky.service;

import com.sky.dto.ShoppingCartDTO;
import com.sky.entity.ShoppingCart;
import java.util.List;

public interface ShoppingCartService {

    /**
     * 添加购物车
     * @param shoppingCartDTO
     */
    void addShoppingCart(ShoppingCartDTO shoppingCartDTO);
}

Service层实现类

创建ShoppingCartServiceImpl实现类，并实现add方法：

java 复制代码

package com.sky.service.impl;


import com.sky.context.BaseContext;
import com.sky.dto.ShoppingCartDTO;
import com.sky.entity.Dish;
import com.sky.entity.Setmeal;
import com.sky.entity.ShoppingCart;
import com.sky.mapper.DishMapper;
import com.sky.mapper.SetmealMapper;
import com.sky.service.ShoppingCartService;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.time.LocalDateTime;
import java.util.List;

@Service
public class ShoppingCartServiceImpl implements ShoppingCartService {

    @Autowired
    private ShoppingCartMapper shoppingCartMapper;
    @Autowired
    private DishMapper dishMapper;
    @Autowired
    private SetmealMapper setmealMapper;
    
    /**
     * 添加购物车
     *
     * @param shoppingCartDTO
     */
    public void addShoppingCart(ShoppingCartDTO shoppingCartDTO) {
        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
        //只能查询自己的购物车数据
        shoppingCart.setUserId(BaseContext.getCurrentId());

        //判断当前商品是否在购物车中
        List<ShoppingCart> shoppingCartList = shoppingCartMapper.list(shoppingCart);

        if (shoppingCartList != null && shoppingCartList.size() == 1) {
            //如果已经存在，就更新数量，数量加1
            shoppingCart = shoppingCartList.get(0);
            shoppingCart.setNumber(shoppingCart.getNumber() + 1);
            shoppingCartMapper.updateNumberById(shoppingCart);
        } else {
            //如果不存在，插入数据，数量就是1

            //判断当前添加到购物车的是菜品还是套餐
            Long dishId = shoppingCartDTO.getDishId();
            if (dishId != null) {
                //添加到购物车的是菜品
                Dish dish = dishMapper.getById(dishId);
                shoppingCart.setName(dish.getName());
                shoppingCart.setImage(dish.getImage());
                shoppingCart.setAmount(dish.getPrice());
            } else {
                //添加到购物车的是套餐
                Setmeal setmeal = setmealMapper.getById(shoppingCartDTO.getSetmealId());
                shoppingCart.setName(setmeal.getName());
                shoppingCart.setImage(setmeal.getImage());
                shoppingCart.setAmount(setmeal.getPrice());
            }
            shoppingCart.setNumber(1);
            shoppingCart.setCreateTime(LocalDateTime.now());
            shoppingCartMapper.insert(shoppingCart);
        }
    }
}

Mapper层

创建ShoppingCartMapper接口:

java 复制代码

package com.sky.mapper;

import com.sky.entity.ShoppingCart;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Update;
import java.util.List;

@Mapper
public interface ShoppingCartMapper {
    /**
     * 条件查询
     *
     * @param shoppingCart
     * @return
     */
    List<ShoppingCart> list(ShoppingCart shoppingCart);

    /**
     * 更新商品数量
     *
     * @param shoppingCart
     */
    @Update("update shopping_cart set number = #{number} where id = #{id}")
    void updateNumberById(ShoppingCart shoppingCart);

    /**
     * 插入购物车数据
     *
     * @param shoppingCart
     */
    @Insert("insert into shopping_cart (name, user_id, dish_id, setmeal_id, dish_flavor, number, amount, image, create_time) " +
            " values (#{name},#{userId},#{dishId},#{setmealId},#{dishFlavor},#{number},#{amount},#{image},#{createTime})")
    void insert(ShoppingCart shoppingCart);

}

创建ShoppingCartMapper.xml：

xml 复制代码

<?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.sky.mapper.ShoppingCartMapper">
    <select id="list" parameterType="ShoppingCart" resultType="ShoppingCart">
        select * from shopping_cart
        <where>
            <if test="userId != null">
                and user_id = #{userId}
            </if>
            <if test="dishId != null">
                and dish_id = #{dishId}
            </if>
            <if test="setmealId != null">
                and setmeal_id = #{setmealId}
            </if>
            <if test="dishFlavor != null">
                and dish_flavor = #{dishFlavor}
            </if>
        </where>
        order by create_time desc
    </select>
</mapper>