Spring Cache 框架给我们提供了 @Cacheable 注解用于缓存方法返回内容。但是 @Cacheable 注解不能定义缓存有效期。这样的话在一些需要自定义缓存有效期的场景就不太实用。

按照 Spring Cache 框架给我们提供的 RedisCacheManager 实现，只能在全局设置缓存有效期。这里给大家看一个常规的 CacheConfig 缓存配置类，代码如下，

@EnableCaching
@Configuration
public class CacheConfig extends CachingConfigurerSupport {...private RedisSerializer<String> keySerializer() {return new StringRedisSerializer();}private RedisSerializer<Object> valueSerializer() {return new GenericFastJsonRedisSerializer();}public static final String CACHE_PREFIX = "crowd:";@Beanpublic CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {// 配置序列化（解决乱码的问题）RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()//设置key为String.serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(keySerializer()))//设置value为自动转Json的Object.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(valueSerializer())).computePrefixWith(name -> CACHE_PREFIX + name  + ":").entryTtl(Duration.ofSeconds(600));RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(Objects.requireNonNull(redisConnectionFactory));return new RedisCacheManager(redisCacheWriter, config);}
}

自定义 MyRedisCacheManager 缓存

其实我们可以通过自定义 MyRedisCacheManager 类继承 Spring Cache 提供的 RedisCacheManager 类后，重写 createRedisCache(String name, RedisCacheConfiguration cacheConfig) 方法来完成自定义缓存有效期的功能，代码如下

public class MyRedisCacheManager extends RedisCacheManager {public MyRedisCacheManager(RedisCacheWriter cacheWriter, RedisCacheConfiguration defaultCacheConfiguration) {super(cacheWriter, defaultCacheConfiguration);}@Overrideprotected RedisCache createRedisCache(String name, RedisCacheConfiguration cacheConfig) {String[] array = StringUtils.split(name, "#");name = array[0];// 解析 @Cacheable 注解的 value 属性用以单独设置有效期if (array.length > 1) {long ttl = Long.parseLong(array[1]);cacheConfig = cacheConfig.entryTtl(Duration.ofSeconds(ttl));}return super.createRedisCache(name, cacheConfig);}
}