黑马苍穹外卖学习Day7

缓存菜品

实现思路

代码开发

Controller层

@RestController("userDishController")
@Api(tags = "C端-菜品浏览接口")
@RequestMapping("/user/dish")
@Slf4j
public class DishController {
    @Autowired
    private DishService dishService;
    @Autowired
    private RedisTemplate redisTemplate;
    /**
     * 根据分类id查询菜品
     * @param categoryId
     * @return
     */
    @GetMapping("/list")
    @ApiOperation("根据分类id查询菜品")
    private 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!=null && list.size() > 0){
            //如果存在直接返回无需查询数据库
            return Result.success(list);
        }

        Dish dish = new Dish();
        dish.setCategoryId(categoryId);
        dish.setStatus(StatusConstant.ENABLE);//查询起售中的菜品
        //如果不存在，查询数据库，将查询数据库插入到redis中
        List<DishVO> dishVOS = dishService.listWithFlavor(dish);
        redisTemplate.opsForValue().set(key, dishVOS);
        return Result.success(dishVOS);
    }
}

在新增菜品，修改菜品，批量删除菜品，起售、停售菜品时候都需要清除缓存以便显示最新数据。
可以在每个Controller方法完成后加上

        Set keys = redisTemplate.keys("dish_*");
        redisTemplate.delete(keys);

可以设计一个清理缓存的方法来替代

    /**
     * 清理缓存数据
     * @param pattern
     */
    private void cleanCache(String pattern){
        Set keys = redisTemplate.keys(pattern);
        redisTemplate.delete(keys);
    }

缓存套餐

Spring Cache

入门案例

根据demo文件创建数据库和对应的表

DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
  `id` bigint NOT NULL AUTO_INCREMENT,
  `name` varchar(45) DEFAULT NULL,
  `age` int DEFAULT NULL,
  PRIMARY KEY (`id`)
);

Controller层

    @Autowired
    private UserMapper userMapper;
    //user.id 动态取到用户id,redis通过冒号储存成树形结构
    @PostMapping
    @CachePut(cacheNames = "userCache",key = "#user.id")  //将方法的返回值放入缓存,key的生成为：userCache::user.id
    //@CachePut(cacheNames = "userCache",key = "#result.id") //对象导航
    //@CachePut(cacheNames = "userCache",key = "#p0.id")//取到第一个参数
    //@CachePut(cacheNames = "userCache",key = "#a0.id")
    public User save(@RequestBody User user){
        userMapper.insert(user);
        return user;
    }

实现类加注解

@Slf4j
@SpringBootApplication
@EnableCaching//开去缓存注解功能
public class CacheDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(CacheDemoApplication.class,args);
        log.info("项目启动成功...");
    }
}

通过Swagger接口测试。

其他的常用注解

@RestController
@RequestMapping("/user")
@Slf4j
public class UserController {

    @Autowired
    private UserMapper userMapper;
    //user.id 动态取到用户id,redis通过冒号储存成树形结构
    @PostMapping
    @CachePut(cacheNames = "userCache",key = "#user.id")  //将方法的返回值放入缓存,key的生成为：userCache::user.id
    //@CachePut(cacheNames = "userCache",key = "#result.id") //对象导航
    //@CachePut(cacheNames = "userCache",key = "#p0.id")//取到第一个参数
    //@CachePut(cacheNames = "userCache",key = "#a0.id")
    public User save(@RequestBody User user){
        userMapper.insert(user);
        return user;
    }
    @CacheEvict(cacheNames = "userCache", key = "#id")
    @DeleteMapping
    public void deleteById(Long id){
        userMapper.deleteById(id);
    }
    @CacheEvict(cacheNames = "userCache" ,allEntries = true)//删除所有键值对缓存
	@DeleteMapping("/delAll")
    public void deleteAll(){
        userMapper.deleteAll();
    }


    @Cacheable(cacheNames = "userCache",key = "#id")//key的生成为：userCache::id
    @GetMapping
    public User getById(Long id){
        User user = userMapper.getById(id);
        return user;
    }

实现思路

代码开发

    @GetMapping("/list")
    @ApiOperation("根据分类id查询套餐")
    @Cacheable(cacheNames = "setmealCache",key = "#categoryId") //key:setmaelCache::categoryId
    public Result<List<Setmeal>> list(Long categoryId){
        List<Setmeal> setmeals = setmealService.list(categoryId);
        return Result.success(setmeals);
    }

    /**
     * 新增套餐接口
     * @param setmealDTO
     * @return
     */
    @PostMapping
    @ApiOperation("新增套餐")
    @CacheEvict(cacheNames = "setmealCache" ,key = "#setmealDTO.categoryId")//key:setmealCache::100
    public Result save(@RequestBody SetmealDTO setmealDTO){
        setmealService.save(setmealDTO);
        return Result.success();
    }

    /**
     * 批量删除套餐
     * @param ids
     * @return
     */
    @DeleteMapping
    @ApiOperation("批量删除套餐")
    @CacheEvict(cacheNames = "setmealCache",allEntries = true)
    public Result delete(@RequestParam List<Long> ids){
        setmealService.deleteBatch(ids);
        return Result.success();
    }
    /**
     * 修改套餐
     * @param setmealDTO
     * @return
     */
    @PutMapping
    @ApiOperation("修改套餐")
    @CacheEvict(cacheNames = "setmealCache",allEntries = true)
    public Result update(@RequestBody SetmealDTO setmealDTO){
        setmealService.update(setmealDTO);
        return Result.success();
    }

添加购物车

需求分析和设计

冗余字段在特定条件下可以提高查询速度，比如这里的name,image,amount等。因为这样不用联表查询只用查这一张表就好了。

代码开发

新建Controller层

@RestController
@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")
    public Result add(@RequestBody ShoppingCartDTO shoppingCartDTO){
        shoppingCartService.addShoppingCart(shoppingCartDTO);
        return Result.success();
    }
}

ServiceImpl

@Slf4j
@Service
public class ShopppingCartServiceImpl implements ShoppingCartService {
    @Autowired
    private ShopppingCartMapper shopppingCartMapper;
    @Autowired
    private DishMapper dishMapper;
    @Autowired
    private SetmealMapper setmealMapper;

    /**
     * 添加购物车
     * @param shoppingCartDTO
     */
    @Override
    public void addShoppingCart(ShoppingCartDTO shoppingCartDTO) {
        //判断当前加入购物车的商品已经存在了
        ShoppingCart shoppingCart =new ShoppingCart();
        BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
        Long userId = BaseContext.getCurrentId();
        shoppingCart.setUserId(userId);
        List<ShoppingCart> list = shopppingCartMapper.list(shoppingCart);
        //如果已经存在了，只需要将数量加一
        if (list != null && list.size() > 0){
            ShoppingCart shoppingCart1 = list.get(0);
            shoppingCart1.setNumber(shoppingCart1.getNumber()+ 1 );//update shopping_cart set number = ? where id = ?
            shopppingCartMapper.updateNumberById(shoppingCart1);
        }else{
            //如果不存在，需要插入一条购物车数据

            //判断本次添加到购物车的是菜品还是套餐
            Long dishId = shoppingCartDTO.getDishId();
            Long setmealId = shoppingCartDTO.getSetmealId();
            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 {
                //本次添加的就是套餐
                Setmeal setmeal = setmealMapper.getById(setmealId);
                shoppingCart.setName(setmeal.getName());
                shoppingCart.setImage(setmeal.getImage());
                shoppingCart.setAmount(setmeal.getPrice());
            }
            shoppingCart.setNumber(1);
            shoppingCart.setCreateTime(LocalDateTime.now());
            //统一插入
            shopppingCartMapper.insert(shoppingCart);
        }

    }
}

Mapper接口

@Mapper
public interface ShopppingCartMapper {
    /**
     * 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);

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

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.ShopppingCartMapper">

    <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>

查看购物车

需求分析

代码开发

Controller层

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

Service实现类

    /**
     * 查看购物车
     * @return
     */
    @Override
    public List<ShoppingCart> showShopppingCart() {
        Long userId = BaseContext.getCurrentId();
        ShoppingCart shoppingCart = ShoppingCart.builder()
                .userId(userId)
                .build();
        List<ShoppingCart> list = shopppingCartMapper.list(shoppingCart);
        return list;
    }

清空购物车

需求分析

代码实现

Controller层

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

Service实现类

    /**
     * 清空购物车
     */
    @Override
    public void cleanShoppingCart() {
        Long userId = BaseContext.getCurrentId();
        shopppingCartMapper.deleteByUserId(userId);
    }

Mapper接口

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