概要

因为商品是经常被浏览的,所以数据库的访问量就问大大增加,造成负载过大影响性能,所以我们需要把商品缓存到redis当中,因为redis是存在内存中的,所以效率会比MySQL的快.

整体架构流程

 

技术细节

• 我们在缓存时需要保持数据的一致性
• 所以当管理端用户进行增删改操作的时候需要清理缓存,否则用户看到的商品则是缓存中的(未被修改的商品)

小结

@GetMapping("/list")
    @ApiOperation("根据分类id查询菜品")
    public Result<List<DishVO>> list(Long categoryId) {
        //缓存菜品
        String key = "dish_" + categoryId;
        List<DishVO> list = (List<DishVO>) redisTemplate.opsForValue().get(key);
        if (list != null && list.size() > 0) {
            return Result.success(list);
        }
        Dish dish = new Dish();
        dish.setCategoryId(categoryId);
        dish.setStatus(StatusConstant.ENABLE);//查询起售中的菜品

        list = dishService.listWithFlavor(dish);
        //如果不存在则查数据库存入redis
        redisTemplate.opsForValue().set(key,list);
        return Result.success(list);
    }

。

package com.sky.controller.admin;

import com.sky.dto.DishDTO;
import com.sky.dto.DishPageQueryDTO;
import com.sky.entity.Dish;
import com.sky.result.PageResult;
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.apache.ibatis.annotations.Delete;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.web.bind.annotation.*;

import javax.websocket.server.PathParam;
import java.util.List;
import java.util.Set;

@RestController
@RequestMapping("admin/dish")
@Slf4j
@Api(tags = "菜品相关接口")
public class DishController {

    @Autowired
    private DishService dishService;
    @Autowired
    private RedisTemplate redisTemplate;

    /**
     * 新增菜品
     * @param dishDTO
     * @return
     */
    @PostMapping
    @ApiOperation("新增菜品")
    public Result save(@RequestBody DishDTO dishDTO){
        Long categoryId = dishDTO.getCategoryId();
        String key = "dish_" + categoryId;
        deleteCache(key);
        dishService.saveWithFlavor(dishDTO);
        return Result.success();
    }

    /**
     * 菜品分页查询
     * @param dishPageQueryDTO
     * @return
     */
    @GetMapping("/page")
    @ApiOperation("菜品分页查询")
    public Result<PageResult> page(DishPageQueryDTO dishPageQueryDTO){
        log.info("菜品分页查询:{}", dishPageQueryDTO);
        PageResult pageResult = dishService.pageQuery(dishPageQueryDTO);
        return Result.success(pageResult);
    }


    /**
     * 批量删除菜品
     * @param ids
     * @return
     */
    @DeleteMapping
    @ApiOperation("批量删除菜品")
    public Result delete(@RequestParam List<Long> ids){
        log.info("批量删除菜品:{}", ids);
        deleteCache("dish_*");
        dishService.deleteBatch(ids);
        return Result.success();
    }

    /**
     * 根据id查询菜品
     * @param id
     * @return
     */
    @GetMapping("/{id}")
    @ApiOperation("根据id查询菜品")
    public Result<DishVO> getById(@PathVariable Long id){
        log.info("根据id查询菜品");
        DishVO dishVO = dishService.getByIdWithFlavor(id);
        return Result.success(dishVO);
    }

    /**
     * 修改菜品
     * @param dishDTO
     * @return
     */
    @PutMapping
    @ApiOperation("修改菜品")
    public Result update(@RequestBody DishDTO dishDTO){
        log.info("修改菜品:{}",dishDTO);
        deleteCache("dish_*");
        dishService.updateWithFlavor(dishDTO);
        return Result.success();
    }

    @GetMapping("/list")
    public Result<List<Dish>> list(@RequestParam Long categoryId){
        log.info("根据分类id查询菜品:{}",categoryId);
        List<Dish> list = dishService.list(categoryId);
        return Result.success(list);
    }

    @PostMapping("/status/{status}")
    @ApiOperation("菜品起售停售")
    public Result<String> startOrStop(@PathVariable Integer status, Long id){
        deleteCache("dish_*");
        dishService.startOrStop(status,id);
        return Result.success();
    }

    private void deleteCache(String pattern){
        Set keys = redisTemplate.keys(pattern);
        redisTemplate.delete(keys);
    }
}