SpringCache

目录

SpringCache

引入

自动配置

自定义配置

注解 

@Cacheable

@CacheEvict​​

sync = true

SpringCache

集成与管理缓存，它通过声明式注解和统一的 API，将缓存逻辑与业务逻辑解耦，支持多种缓存实现（如 Redis、Ehcache、Caffeine 等），并提供了灵活的配置选项。

引入

  org.springframework.boot spring-boot-starter-cache 

@EnableCaching开启缓存

自动配置

CacheAutoConfiguration 依据缓存类型，自动配置缓存。

CacheConfigurations 映射 相应的缓存配置

 static { Map<CacheType, Class> mappings = new EnumMap(CacheType.class); mappings.put(CacheType.GENERIC, GenericCacheConfiguration.class); mappings.put(CacheType.EHCACHE, EhCacheCacheConfiguration.class); mappings.put(CacheType.HAZELCAST, HazelcastCacheConfiguration.class); mappings.put(CacheType.INFINISPAN, InfinispanCacheConfiguration.class); mappings.put(CacheType.JCACHE, JCacheCacheConfiguration.class); mappings.put(CacheType.COUCHBASE, CouchbaseCacheConfiguration.class); mappings.put(CacheType.REDIS, RedisCacheConfiguration.class); mappings.put(CacheType.CAFFEINE, CaffeineCacheConfiguration.class); mappings.put(CacheType.SIMPLE, SimpleCacheConfiguration.class); mappings.put(CacheType.NONE, NoOpCacheConfiguration.class); MAPPINGS = Collections.unmodifiableMap(mappings); }

RedisCacheConfiguration 为每一个缓存\"分区\" 提供初始化，并返回Manager

 @Bean public RedisCacheManager cacheManager(RedisConnectionFactory redisConnectionFactory, ResourceLoader resourceLoader) { RedisCacheManager.RedisCacheManagerBuilder builder = RedisCacheManager.builder(redisConnectionFactory).cacheDefaults(this.determineConfiguration(resourceLoader.getClassLoader())); List cacheNames = this.cacheProperties.getCacheNames(); if (!cacheNames.isEmpty()) { builder.initialCacheNames(new LinkedHashSet(cacheNames)); } return (RedisCacheManager)this.customizerInvoker.customize(builder.build()); }

Manager为每一个分区进行默认配置defaultCacheConfiguration

 public RedisCacheManagerBuilder initialCacheNames(Set cacheNames) { Assert.notNull(cacheNames, \"CacheNames must not be null!\"); Map cacheConfigMap = new LinkedHashMap(cacheNames.size()); cacheNames.forEach((it) -> { RedisCacheConfiguration var10000 = (RedisCacheConfiguration)cacheConfigMap.put(it, this.defaultCacheConfiguration); }); return this.withInitialCacheConfigurations(cacheConfigMap); }

redisCacheConfiguration 若为空，这采用默认配置

 private org.springframework.data.redis.cache.RedisCacheConfiguration determineConfiguration(ClassLoader classLoader) { if (this.redisCacheConfiguration != null) { return this.redisCacheConfiguration; } else { CacheProperties.Redis redisProperties = this.cacheProperties.getRedis(); org.springframework.data.redis.cache.RedisCacheConfiguration config = org.springframework.data.redis.cache.RedisCacheConfiguration.defaultCacheConfig(); config = config.serializeValuesWith(SerializationPair.fromSerializer(new JdkSerializationRedisSerializer(classLoader))); if (redisProperties.getTimeToLive() != null) { config = config.entryTtl(redisProperties.getTimeToLive()); } if (redisProperties.getKeyPrefix() != null) { config = config.prefixKeysWith(redisProperties.getKeyPrefix()); } if (!redisProperties.isCacheNullValues()) { config = config.disableCachingNullValues(); } if (!redisProperties.isUseKeyPrefix()) { config = config.disableKeyPrefix(); } return config; } }

自定义配置

容器中注入一个 RedisCacheConfiguration

@EnableCaching@Configurationpublic class MyCacheConfig { @Autowired private CacheProperties cacheProperties; @Bean RedisCacheConfiguration redisCacheConfiguration(){ RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig(); config = config.serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(new StringRedisSerializer())); //Json序列化 config = config.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new GenericFastJsonRedisSerializer())); //使配置文件生效 CacheProperties.Redis redisProperties = this.cacheProperties.getRedis(); if (redisProperties.getTimeToLive() != null) { config = config.entryTtl(redisProperties.getTimeToLive()); } if (redisProperties.getKeyPrefix() != null) { config = config.prefixKeysWith(redisProperties.getKeyPrefix()); } if (!redisProperties.isCacheNullValues()) { config = config.disableCachingNullValues(); } if (!redisProperties.isUseKeyPrefix()) { config = config.disableKeyPrefix(); } return config; }}

spring.cache.type=redis#缓存空值，防止缓存穿透spring.cache.redis.cache-null-values=true#spring.cache.redis.time-to-live=3600000#spring.cache.redis.key-prefix=CACHE_spring.cache.redis.use-key-prefix=true

注解 

@Cacheable

缓存方法返回值，若缓存命中则直接返回结果，否则执行方法并缓存结果。

键名 默认格式 缓存名::SimpleKey[param1, param2,...]，支持 SpEL 表达式

@Cacheable(key = \"#id\")  // 使用参数 id 作为键@Cacheable(key = \"#user.id\")  // 使用对象属性作为键@Cacheable(key = \"#root.methodName\") // 使用方法名作为键[1,3](@ref)

默认使用jdk序列化机制，可在自定义配置中使用Json序列化器

@CacheEvict​​

清除缓存数据

sync = true

 同步锁，本地锁，仅@Cacheable支持

@Cacheable(cacheNames = \"category\",key = \"#root.methodName\",sync = true)