一、缓存商品

2、缓存菜品（redis）

1.问题说明

2.实现思路

3.代码开发

修改user端的dishController下的根据分类id查询菜品方法：

    /**
     * 根据分类id查询菜品
     * @param categoryId
     * @return
     */
    @GetMapping("/list")
    @ApiOperation("根据分类id查询菜品")
    public Result<List<DishVO>> list(Long categoryId){
        //构造redis中的key，规则：dish_分类id
        String key = "dish_" + categoryId;
        //查询redis中是否存在菜品数据
        List<DishVO> list = (List<DishVO>) redisTemplate.opsForValue().get(key);
        if(list.size() > 0 && list != null){
            //如果存在直接返回
            return Result.success(list);
        }
        //如果不存在，查询数据库，并把数据放入redis
        Dish dish = new Dish();
        dish.setCategoryId(categoryId);
        dish.setStatus(StatusConstant.ENABLE);//查询在起售中的商品
        //如果不存在，查询数据库，并把数据放入redis
        list = dishService.listWithFlavor(dish);
        redisTemplate.opsForValue().set(key, list);
        return Result.success(list);
    }

同时，当新增菜品，修改菜品等操作时，也需要清理缓存数据：
admin下的dishController：

2、缓存套餐（spring cache）

1.实现思路

2.代码实现

在启动类上开启缓存注解

在相应需要使用缓存的地方加上注解：

用户端查询套餐

管理端添加，修改，删除套餐

3、测试

重新加载页面，可以看到redis缓存的数据

二、购物车功能

1、添加购物车

1.需求分析设计

2.代码开发

创建接收数据的DTO：ShoppingCartDTO

@Data
public class ShoppingCartDTO implements Serializable {

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

}

以及连接数据库购物车表的实体类

public class ShoppingCart implements Serializable {

    private static final long serialVersionUID = 1L;

    private Long id;

    //名称
    private String name;

    //用户id
    private Long userId;

    //菜品id
    private Long dishId;

    //套餐id
    private Long setmealId;

    //口味
    private String dishFlavor;

    //数量
    private Integer number;

    //金额
    private BigDecimal amount;

    //图片
    private String image;

    private LocalDateTime createTime;
}

ShoppingCartController

@RestController("userShoppingCartController")
@RequestMapping("/user/shoppingCart")
@Slf4j
@Api(tags = "C端购物车相关接口")
public class ShoppingCartController {


    @Autowired
    private ShoppingCartService shoppingCartService;

    /**
     * 添加购物车
     * @param shoppingCartDTO
     * @return
     */
    @PostMapping("/add")
    @ApiOperation("添加购物车商品")
    public Result add(@RequestBody ShoppingCartDTO shoppingCartDTO){
        log.info("添加购物车，商品信息为：{}",shoppingCartDTO);
        shoppingCartService.addShoppingCart(shoppingCartDTO);
        return Result.success();
    }
}

ShoppingCartService：

public interface ShoppingCartService {

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

ShoppingCartServiceImpl：

@Service
@Slf4j
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 addShoppingCart(ShoppingCartDTO shoppingCartDTO) {
        //判读当前加入购物车中的商品是否已经存在
        ShoppingCart shoppingCart = new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO,shoppingCart);
        Long userId = BaseContext.getCurrentId();
        shoppingCart.setUserId(userId);
        List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart);
        //如果已经存在，只需要数量＋1
        if(list.size() > 0 && list != null){
            ShoppingCart cart = list.get(0);
            cart.setNumber(cart.getNumber() + 1);
            shoppingCartMapper.updateNumberById(cart);
        }else {
            //如果不存在，则插入一条购物车数据

            //判读本次添加购物车的时菜品还是套餐
            Long dishId = shoppingCartDTO.getDishId();
            if(dishId != null){
                //本次添加的是菜品
                Dish dish = dishMapper.getById(dishId);
                shoppingCart.setName(dish.getName());
                shoppingCart.setImage(dish.getImage());
                shoppingCart.setAmount(dish.getPrice());
                shoppingCart.setNumber(1);
                shoppingCart.setCreateTime(LocalDateTime.now());
            }else {
                //本次添加的是套餐
                Long setmealId = shoppingCartDTO.getSetmealId();
                Setmeal setmeal = setmealMapper.getById(setmealId);
                shoppingCart.setName(setmeal.getName());
                shoppingCart.setImage(setmeal.getImage());
                shoppingCart.setAmount(setmeal.getPrice());
                shoppingCart.setNumber(1);
                shoppingCart.setCreateTime(LocalDateTime.now());
            }
            shoppingCartMapper.insert(shoppingCart);
        }

    }
 }

ShoppingCartMapper：

@Mapper
public interface ShoppingCartMapper {

    /**
     * 动态条件查询
     * @param shoppingCart
     * @return
     */
    List<ShoppingCart> list(ShoppingCart shoppingCart);

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

    /**
     * 添加购物车数据
     * @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);
 }

ShoppingCartMapper.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" resultType="com.sky.entity.ShoppingCart">
        select * from shopping_cart
        <where>
            <if test="userId != null">
                and user_id = #{userId}
            </if>
            <if test="setmealId != null">
                and setmeal_id = #{setmealId}
            </if>
            <if test="dishId != null">
                and dish_id = #{dishId}
            </if>
            <if test="dishFlavor != null">
                and dish_flavor = #{dishFlavor}
            </if>
        </where>
    </select>
</mapper>

3.测试

选择商品加入购物车

可以看到数据库中已经有数据了，则添加成功

并且添加两个套餐后

2、查看购物车

1.需求分析设计

2.代码开发

ShoppingCartController：

    /**
     * 查看购物车
     * @return
     */
    @GetMapping("/list")
    @ApiOperation("查看购物车")
    public Result<List<ShoppingCart>> list(){
        List<ShoppingCart> shoppingCarts = shoppingCartService.showShoppingCart();
        return Result.success(shoppingCarts);
    }

ShoppingCartService：

    /**
     * 查看购物车
     * @return
     */
    List<ShoppingCart> showShoppingCart();

ShoppingCartServiceImpl：

    /**
     * 查看购物车
     * @return
     */
    @Override
    public List<ShoppingCart> showShoppingCart() {
        //获取用户id
        Long userId = BaseContext.getCurrentId();
        ShoppingCart shoppingCart = ShoppingCart.builder()
                .userId(userId)
                .build();
        List<ShoppingCart> list = shoppingCartMapper.list(shoppingCart);
        return list;
    }

3.测试

可以看到购物车回显数据

3、清空购物车

1.需求分析设计

2.代码设计

ShoppingCartController：

    /**
     * 清空购物车
     * @return
     */
    @DeleteMapping("/clean")
    @ApiOperation("清空购物车")
    public Result clean(){
        shoppingCartService.cleanShoppingCart();
        return Result.success();
    }

ShoppingCartService：

    /**
     * 清空购物车
     */
    void cleanShoppingCart();

ShoppingCartServiceImpl：

    /**
     * 清空购物车
     */
    @Override
    public void cleanShoppingCart() {
        //获取用户id
        Long userId = BaseContext.getCurrentId();
        shoppingCartMapper.deleteByUserId(userId);
    }

ShoppingCartMapper：

    /**
     * 清空购物车
     * @param userId
     */
    @Delete("delete from shopping_cart where user_id = #{userId}")
    void deleteByUserId(Long userId);

3.测试

点击清空购物车

三、相关知识

1、Spring Cache实现注解缓存功能

具体用法：
启动类上开启springcache功能

CachePut的多种生成缓存方法

同理Cacheable


CacheEvict删除所有缓存