个人项目购物卡Impl实现逻辑

/**
     * 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);
        }
    }
    /**
     * 从购物车减去
     *
     * @param shoppingCartDTO
     */
    public void subShoppingCart(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-1
            shoppingCart = shoppingCartList.get(0);
            shoppingCart.setNumber(shoppingCart.getNumber() - 1);
            shoppingCartMapper.updateNumberById(shoppingCart);
        } else {
            //如果不存在
            shoppingCartMapper.delete(shoppingCart);
            }
        }
    /**
     * 查看购物车
     * @return
     */
    public List<ShoppingCart> showShoppingCart() {
        return shoppingCartMapper.list(ShoppingCart.
                builder().
                userId(BaseContext.getCurrentId()).
                build());
    }
    /**
     * 清空购物车商品
     */
    public void cleanShoppingCart() {
        shoppingCartMapper.deleteByUserId(BaseContext.getCurrentId());
    }

service

/**
     * 添加购物车
     * @param shoppingCartDTO
     */
    void addShoppingCart(ShoppingCartDTO shoppingCartDTO);
    /**
     * 从购物车减去
     * @param shoppingCartDTO
     */
    void subShoppingCart(ShoppingCartDTO shoppingCartDTO);
    /**
     * 查看购物车
     * @return
     */
    List<ShoppingCart> showShoppingCart();
    /**
     * 清空购物车商品
     */
    void cleanShoppingCart();

 XML

<?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>
    <insert id="insertBatch" parameterType="list">
        insert into shopping_cart
        (name, image, user_id, dish_id, setmeal_id, dish_flavor, number, amount, create_time)
        values
        <foreach collection="shoppingCartList" item="sc" separator=",">
            (#{sc.name},#{sc.image},#{sc.userId},#{sc.dishId},#{sc.setmealId},#{sc.dishFlavor},#{sc.number},#{sc.amount},#{sc.createTime})
        </foreach>
    </insert>
</mapper>

controller

/**
 * 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();
    }
//    减菜品
    /**
     * 从购物车减去
     * @param shoppingCartDTO
     * @return
     */
    @PostMapping("/sub")
    @ApiOperation("从购物车减去")
    public Result<String> sub(@RequestBody ShoppingCartDTO shoppingCartDTO){
        log.info("从购物车减去：{}", shoppingCartDTO);
        shoppingCartService.subShoppingCart(shoppingCartDTO);//后绪步骤实现
        return Result.success();
    }
    /**
     * 查看购物车
     * @return
     */
    @GetMapping("/list")
    @ApiOperation("查看购物车")
    public Result<List<ShoppingCart>> list(){
        return Result.success(shoppingCartService.showShoppingCart());
    }
    /**
     * 清空购物车商品
     * @return
     */
    @DeleteMapping("/clean")
    @ApiOperation("清空购物车商品")
    public Result<String> clean(){
        shoppingCartService.cleanShoppingCart();
        return Result.success();
    }