缓存菜品
问题说明
用户端小程序展示的菜品数据都是通过查询数据库获得，如果用户端访问量比较大，数据库访问压力随之增大。
结果：系统响应慢，用户体验差
实现思路
通过 Redis 来缓存菜品数据，减少数据库查询操作。
缓存逻辑分析：
每个分类下的菜品保存一份缓存数据
数据库中菜品数据有变更时清理缓存数据
代码开发
首先是菜品缓存
package com.sky.controller.user;
import com.sky.constant.StatusConstant;
import com.sky.entity.Dish;
import com.sky.result.Result;
import com.sky.service.DishService;
import com.sky.vo.DishVO;
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.data.redis.core.RedisTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@RestController("userDishController")
@RequestMapping("/user/dish")
@Slf4j
@Api(tags = "C端-菜品浏览接口")
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")
public Result<List<DishVO>> list(Long categoryId) {
//构造 redis 中的 key
String key = "dish_" + categoryId;
//查询 redis 中是否存在这个 key 的 value
List<DishVO> list = (List<DishVO>)redisTemplate.opsForValue().get(key);
if(list != null && list.size() > 0){
//如果这个 key 在 redis 中存在，就不去查 mysql，直接返回
return Result.success(list);
}
Dish dish = new Dish();
dish.setCategoryId(categoryId);
dish.setStatus(StatusConstant.ENABLE);//查询起售中的菜品
//redis 中没有的话，就去 mysql 里面查，查到之后就存入 redis
list = dishService.listWithFlavor(dish);
redisTemplate.opsForValue().set(key, list);
return Result.success(list);
}
}
为了保证 mysql 和 redis 中的数据库的数据一致，我们需要清理缓存，所以当我们进行修改，删除，起/停售，新增菜品 操作时需要清空缓存，为了代码简洁我们直接写一个方法，直接调用这个方法即可
/**
* 清空缓存
*/
private void DeleteRedis(String pattern){
Set keys = redisTemplate.keys(pattern);
redisTemplate.delete(keys);
}功能测试
当我们调用该方法时，可以发现 Redis 里面的 key 消失了
缓存套餐
Spring Cache
实现思路
代码开发
@Cacheable(cacheNames = "setmealCache", key = "#categoryId") // key: setmealCache::categoryId
@GetMapping("/list")
@ApiOperation("根据分类id查询套餐")
public Result<List<Setmeal>> list(Long categoryId) {
Setmeal setmeal = new Setmeal();
setmeal.setCategoryId(categoryId);
setmeal.setStatus(StatusConstant.ENABLE);
List<Setmeal> list = setmealService.list(setmeal);
return Result.success(list);
} @PostMapping
@ApiOperation("新增套餐")
@CacheEvict(cacheNames = "setmealCache", key = "setmealDTO.categoryId")
public Result save(@RequestBody SetmealDTO setmealDTO) {
setmealService.saveWithDish(setmealDTO);
return Result.success();
} @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();
} @PutMapping
@ApiOperation("修改套餐")
@CacheEvict(cacheNames = "setmealCache", allEntries = true)
public Result update(@RequestBody SetmealDTO setmealDTO) {
setmealService.update(setmealDTO);
return Result.success();
} @PostMapping("/status/{status}")
@ApiOperation("套餐起售停售")
@CacheEvict(cacheNames = "setmealCache", allEntries = true)
public Result startOrStop(@PathVariable Integer status, Long id) {
setmealService.startOrStop(status, id);
return Result.success();
}功能测试
和之前缓存菜品一样，只需要看一下 Redis 里面是否缓存成功即可
添加购物车
需求分析和设计
代码开发
具体业务逻辑见代码
package com.sky.controller.user;
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.data.redis.core.RedisTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController("userShopController")
@RequestMapping("/user/shop")
@Slf4j
@Api(tags = "用户端店铺营业状态相关接口")
public class ShopController {
@Autowired
RedisTemplate redisTemplate;
public static final String KEY = "SHOP_STATUS";
@GetMapping("/status")
@ApiOperation("营业状态查询")
public Result<Integer> result(){
Integer status = (Integer) redisTemplate.opsForValue().get(KEY);
log.info("当前店铺的营业状态为：{}", status == 1 ? "营业中": "打样中");
return Result.success(status);
}
}
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.ShopCartMapper;
import com.sky.service.ShopCardService;
import lombok.extern.slf4j.Slf4j;
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;
@Slf4j
@Service
public class ShopCardServiceImpl implements ShopCardService {
@Autowired
ShopCartMapper shopCartMapper;
@Autowired
DishMapper dishMapper;
@Autowired
SetmealMapper setmealMapper;
@Override
public void add(ShoppingCartDTO shoppingCartDTO) {
ShoppingCart shoppingCart = new ShoppingCart();
BeanUtils.copyProperties(shoppingCartDTO, shoppingCart);
shoppingCart.setUserId(BaseContext.getCurrentId());
// 首先判断要添加的是菜品还是套餐
Long dishId = shoppingCartDTO.getDishId();
Long setmealId = shoppingCartDTO.getSetmealId();
if(dishId != null){
// 传入的是菜品,判断购物车里是否有该菜品
List<ShoppingCart> list = shopCartMapper.list(shoppingCart);
// 菜品不为空，说明菜品已经存在，我们只需要让它的数量 + 1
if(list != null && list.size() > 0){
//注意注意，因为这张表里每个菜品只能存一次，所以我的这个集合要么没有元素，要么只有一个元素
// 所以第一个元素也就是我们需要修改的那个
ShoppingCart shoppingCart1 = list.get(0);
shoppingCart.setNumber(shoppingCart1.getNumber() + 1);
shoppingCart.setId(shoppingCart1.getId());
// log.info("当前菜品的数量为：{}", shoppingCart.getNumber());
// log.info("当前菜品的 id 为：{}",shoppingCart.getId());
shopCartMapper.update(shoppingCart);
return;
}else{
// 菜品为空，我们就需要查找对应的菜品数据，然后赋值给 shoppingCart
Dish dish = dishMapper.getById(dishId);
shoppingCart.setNumber(1);
shoppingCart.setAmount(dish.getPrice());
shoppingCart.setCreateTime(LocalDateTime.now());
shoppingCart.setName(dish.getName());
shoppingCart.setImage(dish.getImage());
shopCartMapper.insert(shoppingCart);
return;
}
}else{
// 传入的是套餐，判断购物车中是否有该套餐,逻辑和上面一样
List<ShoppingCart> list = shopCartMapper.list(shoppingCart);
if(list != null && list.size() > 0){
ShoppingCart shoppingCart1 = list.get(0);
shoppingCart.setNumber(shoppingCart1.getNumber() + 1);
shoppingCart.setId(shoppingCart1.getId());
shopCartMapper.update(shoppingCart);
return;
}else{
// 套餐为空
Setmeal setmeal = setmealMapper.getById(setmealId);
shoppingCart.setNumber(1);
shoppingCart.setAmount(setmeal.getPrice());
shoppingCart.setCreateTime(LocalDateTime.now());
shoppingCart.setName(setmeal.getName());
shoppingCart.setImage(setmeal.getImage());
shopCartMapper.insert(shoppingCart);
return;
}
}
}
}
package com.sky.mapper;
import com.sky.entity.ShoppingCart;
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 ShopCartMapper {
List<ShoppingCart> list(ShoppingCart shoppingCart);
@Update("update sky_take_out.shopping_cart set number = #{number} where id = #{id}")
void update(ShoppingCart shoppingCart);
@Insert("insert into sky_take_out.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 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.ShopCartMapper">
<select id="list" resultType="com.sky.entity.ShoppingCart">
select * from sky_take_out.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>
功能测试
查看购物车
需求分析和设计
代码开发
@GetMapping("/list")
@ApiOperation("查看购物车信息")
public Result<List<ShoppingCart>> showShoppingCart(){
List<ShoppingCart> shoppingCart = shopCardService.list();
return Result.success(shoppingCart);
}
@Override
public List<ShoppingCart> list() {
ShoppingCart shoppingCart = ShoppingCart.builder()
.userId(BaseContext.getCurrentId())
.build();
List<ShoppingCart> shoppingCarts = shopCartMapper.list(shoppingCart);
return shoppingCarts;
}<?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.ShopCartMapper">
<select id="list" resultType="com.sky.entity.ShoppingCart">
select * from sky_take_out.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>
功能测试
清空购物车
需求分析和设计
代码开发
@DeleteMapping("/clean")
@ApiOperation("清空购物车")
public Result clearShoppingCart(){
log.info("清空购物车");
shopCardService.clean();
return Result.success();
} @Override
public void clean() {
shopCartMapper.clean(BaseContext.getCurrentId());
} @Delete("delete from sky_take_out.shopping_cart where user_id = #{currentId}")
void clean(Long currentId);功能测试
直接可以看到数据库中的数据被删除了