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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 {@Resourceprivate DicValueService dicValueService;@Resourceprivate UserService userService;@Resourceprivate 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);}
}