封装redis工具类代码

package com.hmdp.utils;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;
import org.springframework.data.redis.core.StringRedisTemplate;
import java.time.LocalDateTime;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.function.Function;
import static com.hmdp.utils.RedisConstants.*;

@Slf4j
@Component
public class CacheClient {
    //建立池子
    private  static  final ExecutorService CACHE_REBUILD_EXECUTOR = Executors.newFixedThreadPool(10);

    private  final StringRedisTemplate stringRedisTemplate;

    public  CacheClient(StringRedisTemplate stringRedisTemplate){
        this.stringRedisTemplate=stringRedisTemplate;
    }

    public  void set(String key, Object value , Long time , TimeUnit unit){
        stringRedisTemplate.opsForValue().set(key, JSONUtil.toJsonStr(value),time,unit);
    }

    public  void setWithLogicalExpire(String key, Object value , Long time , TimeUnit unit){
        //设置逻辑过期
        RedisData redisData = new RedisData();
        redisData.setData(value);
        redisData.setExpireTime(LocalDateTime.now().plusSeconds(unit.toSeconds(time)));
        //写入Redis
        stringRedisTemplate.opsForValue().set(key, JSONUtil.toJsonStr(redisData));
    }

    //中，ID为参数，R为返回值
    public  R queryWithPassThrough(String keyPrefix , ID id , Class type, Function dbFallback,Long time , TimeUnit unit ) {
        String key = keyPrefix + id;
        //1,从redis查询商铺缓存
        String json = stringRedisTemplate.opsForValue().get(key);
        //2，判断是否存在
        if (StrUtil.isNotBlank(json)) {
            //3，存在，直接返回
            return JSONUtil.toBean(json, type);
        }
        //判断命中的是否是空值
        if (json != null) {
            //返回一个错误信息
            return null;
        }
        //4，不存在，根据id查询数据库
        R r = dbFallback.apply(id);
        //5，不存在，返回错误
        if (r == null) {
            //将空值写入redis
            stringRedisTemplate.opsForValue().set(key, "", CACHE_NULL_TTL, TimeUnit.MINUTES);
            //返回错误信息
            return null;
        }
        //6，存在，写入redis
        this.set(key,r,time,unit);
        //7，返回
        return r;
    }
    public   R queryWithLogicalExpire(String keyPrefix , ID id , Class type, Function dbFallback,Long time , TimeUnit unit) {
        String key = keyPrefix + id;
        //1,从redis查询商铺缓存
        String json = stringRedisTemplate.opsForValue().get(key);
        //2，判断是否存在
        if (StrUtil.isBlank(json)) {
            //3，存在，直接返回
            return null;
        }
        //4，命中，需要先把json反序列化为对象
        RedisData redisData = JSONUtil.toBean(json, RedisData.class);
        R r = JSONUtil.toBean((JSONObject) redisData.getData(), type);
        LocalDateTime expireTime = redisData.getExpireTime();
        //5，判断是否过期
        if (expireTime.isAfter(LocalDateTime.now())) {
            //5.1 未过期，直接返回店铺信息
            return r;
        }
        //5.2已过期，需要缓存重建
        //6.缓存重建
        //6.1，获取互斥锁
        String lockKey = LOCK_SHOP_KEY + id;
        boolean isLock = tryLock(lockKey);
        //6.2，判断是否获取锁成功
        if (isLock) {
            //6.3 成功，开启独立线程，实现缓存重建
            CACHE_REBUILD_EXECUTOR.submit(() -> {
                try {
                    //查询数据库
                    R r1 =dbFallback.apply(id);
                    //写入redis
                    this.setWithLogicalExpire(key,r1,time,unit);
                } catch (Exception e) {
                    throw new RuntimeException(e);
                }finally {
                    //释放锁
                    unlock(lockKey);
                }
            });
        }
        //6.4 返回过期的商铺信息
        return r;
    }

    private boolean tryLock(String key) {
        Boolean flag = stringRedisTemplate.opsForValue().setIfAbsent(key, "1", 10, TimeUnit.SECONDS);
        return BooleanUtil.isTrue(flag);
    }

    private void unlock(String key) {
        stringRedisTemplate.delete(key);
    }
}

@Service
public class ShopServiceImpl extends ServiceImpl implements IShopService {
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private CacheClient cacheClient;

    @Override
    public Result queryById(Long id) {
        //解决缓存穿透

        //互斥锁解决缓存穿透
        //Shop shop = cacheClient.queryWithPassThrough(CACHE_SHOP_KEY , id , Shop.class , this::getById,CACHE_SHOP_TTL,TimeUnit.MINUTES);

        //逻辑过期解决缓存穿透
        Shop shop= cacheClient.queryWithLogicalExpire(CACHE_SHOP_KEY , id , Shop.class , this::getById,CACHE_SHOP_TTL,TimeUnit.MINUTES);
        if (shop == null) {
            return Result.fail("店铺不存在！");
        }
        //7，返回
        return Result.ok(shop);
    }

应该问题不大//