缓存工具类

背景

写oj系统过程中，需要使用缓存工具类。其功能为，先从缓存中获取数据，如数据不存在，从数据库中获取。

代码

package xyz.wry.utils;

import org.springframework.util.ObjectUtils;

import java.util.function.Consumer;
import java.util.function.Supplier;

/**
 * @author wry
 * @Description 缓存层查询工具
 * @create 2025-03-13 13:25
 */
public class CacheUtil {

    /**
     * 缓存读数据且更新
     * @param cacheSelector 从缓存中读数据
     * @param dbSelector 从数据库中读数据
     * @param saveCache 保存缓存
     * @return 数据
     * @param <T> entityVo
     */
    public static <T> T getCacheData (Supplier<T> cacheSelector, Supplier<T> dbSelector, Consumer<T> saveCache) {
        // 从缓存中读数据
        T data = cacheSelector.get();
        if (ObjectUtils.isEmpty(data)) {
            // 空数据,则从数据库中读数据
            data = dbSelector.get();
            if (ObjectUtils.isEmpty(data)) {
                // 数据写入缓存
                saveCache.accept(data);
            }
        }
        return data;
    }
}

使用

package xyz.wry.controller;

import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.fasterxml.jackson.core.JsonProcessingException;
import jakarta.annotation.Resource;
import org.springframework.beans.BeanUtils;
import org.springframework.util.ObjectUtils;
import org.springframework.web.bind.annotation.*;
import xyz.wry.manage.impl.DicManager;
import xyz.wry.model.dto.dicValue.DicValueAddDto;
import xyz.wry.model.dto.dicValue.DicValueEditDto;
import xyz.wry.model.dto.dicValue.DicValueQueryDto;
import xyz.wry.model.dto.result.Result;
import xyz.wry.model.entity.DicValue;
import xyz.wry.model.vo.DicValueVo;
import xyz.wry.service.DicValueService;
import xyz.wry.service.UserService;
import xyz.wry.utils.CacheUtil;

import java.util.Date;
import java.util.List;

/**
 * @author wry
 * @Description 问题Controller
 * @create 2025-03-05 21:35
 */
@RestController
@RequestMapping("/dicValue")
public class DicValueController {

    @Resource
    private DicValueService dicValueService;

    @Resource
    private UserService userService;

    @Resource
    private DicManager dicManager;

    /**
     * 根据dicName获取字典值列表
     *
     * @param dicName
     * @return
     */
    @GetMapping("/dicName/{dicName}")
    public Result<List<DicValueVo>> getDicValueListByDicName(@PathVariable String dicName) {
        List<DicValueVo> dicValueVoList = CacheUtil.getCacheData(
                () -> dicManager.getDicValueListByDicName(dicName),
                () -> dicValueService.getDicValueListByDicName(dicName),
                data -> {
                    try {
                        dicManager.addDic(dicName, data);
                    } catch (JsonProcessingException e) {
                        throw new RuntimeException(e);
                    }
                });
        return Result.success(dicValueVoList);
    }
}