51工具盒子一身报国有万死，双鬓向人无再青。 ------ 陆游
封装了一个操作redis的管理层，简单处理了缓存穿透、击穿、雪崩问题
Manager
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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 | hljs java package com.ruben.manager; import com.alibaba.fastjson.TypeReference; import java.util.function.Supplier; /** * redis管理层 * * @author <achao1441470436@gmail.com> * @since 2021/6/11 0011 21:55 */ public interface RedisManager { /** * 从缓存中获取否则从mysql中查询 * * @param key 缓存中的key * @param mysqlSupplier 查询mysql操作 * @param typeReference 返回的类型 * @param <T> 数据类型 * @return 数据 */ <T> T getFromRedisOrPutIntoMysql(String key, Supplier<T> mysqlSupplier, TypeReference<T> typeReference); } |
实现类
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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 | hljs java package com.ruben.manager; import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.TypeReference; import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException; import com.ruben.utils.Opt; import org.apache.commons.lang3.StringUtils; import org.springframework.data.redis.core.StringRedisTemplate; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Isolation; import org.springframework.transaction.annotation.Propagation; import org.springframework.transaction.annotation.Transactional; import javax.annotation.Resource; import java.security.SecureRandom; import java.util.Objects; import java.util.concurrent.TimeUnit; import java.util.function.Supplier; /** * redis管理层实现类 * * @author <achao1441470436@gmail.com> * @since 2021/6/11 0011 21:55 */ @Service public class RedisManagerImpl implements RedisManager { public static final SecureRandom SECURE_RANDOM = new SecureRandom(); /** * 过期时间 */ public static final int EXPIRE_SECONDS = 5 * 60 * 1000; @Resource private StringRedisTemplate stringRedisTemplate; /** * 从缓存中获取否则从mysql中查询 * * @param key 缓存中的key * @param mysqlSupplier 查询mysql操作 * @param typeReference 返回的类型 * @param <T> 数据类型 * @return 数据 */ @Override @Transactional(readOnly = true, propagation = Propagation.NOT_SUPPORTED, isolation = Isolation.READ_UNCOMMITTED) public <T> T getFromRedisOrPutIntoMysql(String key, Supplier<T> mysqlSupplier, TypeReference<T> typeReference) { // 判断传入key是否为空 Opt.ofNullable(key).filter(StringUtils::isNotEmpty) .orElseThrow(() -> new MybatisPlusException("key不能为空")); // 如果redis中存在，直接返回 String value = stringRedisTemplate.opsForValue().get(key); if (Objects.nonNull(value)) { return JSON.parseObject(value, typeReference); } // 查数据库并放入缓存这个操作加锁【缓存击穿】 synchronized (this) { // 否则从数据库中取出 return Opt.ofNullable(mysqlSupplier).map(Supplier::get) // 如果有值则放入缓存，随机时间【缓存雪崩】 .peek(v -> stringRedisTemplate.opsForValue() .set(key, JSON.toJSONString(v), SECURE_RANDOM.nextInt(EXPIRE_SECONDS), TimeUnit.SECONDS)) // 没值则放入空对象"{}"【缓存穿透】并返回null .orElseGet(() -> { stringRedisTemplate.opsForValue() .set(key, "{}", SECURE_RANDOM.nextInt(EXPIRE_SECONDS), TimeUnit.SECONDS); return null; }); } } } |
使用方式
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| 1 2 3 4 5 6 7 8 9 10 11 12 | hljs java @Resource private RedisManager redisManager; @Test public void managerTest() { List<String> userIds = redisManager.getFromRedisOrPutIntoMysql("userIds", () -> { // 从数据库中查询... return Arrays.asList("1", "2", "3"); }, new TypeReference<List<String>>() { }); System.out.println(userIds); } |
目前自己开发中用着感觉还不错的，大伙可以拿去自定义
