一.查看购物车
查看购物车使用get请求。我们要查看当前用户的购物车，就要获取当前用户的userId字段进行条件查询。因为在用户登录时就已经将userId封装在token中了，因此我们只需要解析token获取userId即可，不需要前端再传入参数了。
Controller层
package com.sky.controller.user;
import com.sky.context.BaseContext;
import com.sky.dto.ShoppingCartDTO;
import com.sky.entity.ShoppingCart;
import com.sky.result.Result;
import com.sky.service.ShoppingCartService;
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.*;
import java.util.List;
@RestController
@RequestMapping("/user/shoppingCart")
@Slf4j
@Api(tags = "购物车相关接口")
public class ShoppingCartController {
@Autowired
private ShoppingCartService shoppingCartService;
/**
* 添加购物车
* @param shoppingCartDTO
* @return
*/
@ApiOperation("添加购物车")
@PostMapping("/add")
public Result add(@RequestBody ShoppingCartDTO shoppingCartDTO) {
log.info("向购物车中添加菜品或套餐：{}",shoppingCartDTO);
shoppingCartService.add(shoppingCartDTO);
return Result.success();
}
/**
* 查看购物车
* @return
*/
@GetMapping("/list")
@ApiOperation("查看购物车")
public Result<List<ShoppingCart>> list() {
log.info("查看购物车：{}", BaseContext.getCurrentId());
List<ShoppingCart> list = shoppingCartService.showShoppingCart();
return Result.success(list);
}
}
返回一个含有当前用户所有购物车信息的列表，列表的元素为购物车对象ShoppingCart。
Service层
接口
package com.sky.service;
import com.sky.dto.ShoppingCartDTO;
import com.sky.entity.ShoppingCart;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public interface ShoppingCartService {
/**
* 添加购物车
* @param shoppingCartDTO
*/
void add(ShoppingCartDTO shoppingCartDTO);
/**
* 查查看购物车
* @return
*/
List<ShoppingCart> showShoppingCart();
}
实现类
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.mapper.ShoppingCartMapper;
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
*/
@Override
public void add(ShoppingCartDTO shoppingCartDTO) {
// 首先判断这次添加购物车的操作加入的菜品或套餐是否已经存在，如果存在就把份数+1，如果不存在就新增
ShoppingCart shoppingCart = new ShoppingCart();
BeanUtils.copyProperties(shoppingCartDTO,shoppingCart);
Long userId = BaseContext.getCurrentId();
shoppingCart.setUserId(userId);
// 1.首先查询该菜品或套餐在数据库中是否存在
List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart); // 每次添加的要么是菜品，要么是套餐。且如果重复添加只会增加份数而不会新增一条数据，因此每次查询要么为空，要么查询出1条数据
if (list != null && list.size() > 0) { // 已存在，数量+1
ShoppingCart cart = list.get(0); // 将已存在的购物车对象取出
cart.setNumber(cart.getNumber() + 1); // 并将其菜品/套餐数量+1
shoppingCartMapper.updateNumberById(cart); // 通过id更新
} else {
// 2.不存在，先判断是套餐还是菜品，因为套餐和菜品在购物车中所需要的属性是不一样的
Long dishId = shoppingCartDTO.getDishId();
if (dishId != null) {
// 3.如果是菜品，那么从菜品数据库中查找并将对应属性赋值给购物车对象
Dish dish = dishMapper.getById(dishId);
shoppingCart.setName(dish.getName());
shoppingCart.setImage(dish.getImage());
shoppingCart.setAmount(dish.getPrice());
} else {
// 4.如果是套餐，那么从套餐数据库中查找并将对应属性赋值给购物车对象
Long setmealId = shoppingCartDTO.getSetmealId();
Setmeal setmeal = setmealMapper.getById(setmealId);
shoppingCart.setName(setmeal.getName());
shoppingCart.setImage(setmeal.getImage());
shoppingCart.setAmount(setmeal.getPrice());
}
// 5.将新增的菜品/套餐加入数据库中
shoppingCart.setNumber(1);
shoppingCart.setCreateTime(LocalDateTime.now());
shoppingCartMapper.insert(shoppingCart);
}
}
/**
* 查看购物车
* @return
*/
@Override
public List<ShoppingCart> showShoppingCart() {
Long userId = BaseContext.getCurrentId();
ShoppingCart shoppingCart = ShoppingCart.builder()
.userId(userId)
.build();
List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart);
return list;
}
}
我们要根据userId来筛选要查看哪个用户的购物车，因此要通过token令牌获得userId，然后构建shoppingCart对象并将该属性赋值，最后通过数据库进行查找符合该用户的购物车列表。
Mapper层
接口
package com.sky.mapper;
import com.sky.dto.ShoppingCartDTO;
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 {
/**
* 查询菜品/套餐是否存在
* @param shoppingCart
* @return
*/
List<ShoppingCart> list(ShoppingCart shoppingCart);
/**
* 更新购物车中套餐/菜品份数
* @param shoppingCart
*/
@Update("update shopping_cart set number = #{number} where id = #{id}")
void updateNumberById(ShoppingCart shoppingCart);
/**
* 向购物车中加入菜品/套餐
* @param shoppingCart
*/
@Insert("insert into shopping_cart(name, image, user_id, dish_id, setmeal_id, dish_flavor, number, amount, create_time) " +
"VALUES (#{name}, #{image}, #{userId}, #{dishId}, #{setmealId}, #{dishFlavor}, #{number}, #{amount},#{createTime})")
void insert(ShoppingCart shoppingCart);
}
XML映射文件
只有userId，根据userId查询即可。
<?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" resultType="com.sky.entity.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>
</select>
</mapper>
成功
