目录

缓存支持

 缓存集成

redis缓存集成

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缓存支持

Spring 框架只提供抽象，不提供具体的缓存存储，底层需要依赖第三方存储组件，如果当前应用没有注册CacheManager 或者 CacheResolver 实例，Spring Boot 会按以下缓存组件的顺序来检测:

1. Generic
2. JCache (SR-107)(EhCache 3, Hazelcast, Infinispan 等等)
3. Hazelcast
4. lnfinispan
5. Couchbase
6. redis

........

Spring Boot的自动配置类为：CacheAutoConfiguration，在 CacheAutoConfiguration 缓存自动配置类中引入了 CacheConfigurationImportSelector 配置选择器：

@AutoConfiguration(after = { CouchbaseDataAutoConfiguration.class, HazelcastAutoConfiguration.class,HibernateJpaAutoConfiguration.class, RedisAutoConfiguration.class })
@ConditionalOnClass(CacheManager.class)
@ConditionalOnBean(CacheAspectSupport.class)
@ConditionalOnMissingBean(value = CacheManager.class, name = "cacheResolver")
@EnableConfigurationProperties(CacheProperties.class)
@Import({ CacheConfigurationImportSelector.class, CacheManagerEntityManagerFactoryDependsOnPostProcessor.class })
public class CacheAutoConfiguration {...static class CacheConfigurationImportSelector implements ImportSelector {@Overridepublic String[] selectImports(AnnotationMetadata importingClassMetadata) {CacheType[] types = CacheType.values();String[] imports = new String[types.length];for (int i = 0; i < types.length; i++) {imports[i] = CacheConfigurations.getConfigurationClass(types[i]);}return imports;}}

该选择器通过 CacheConfiqurations 缓存配置类来选择对应缓存组件的配置类：

final class CacheConfigurations {private static final Map<CacheType, String> MAPPINGS;static {Map<CacheType, String> mappings = new EnumMap<>(CacheType.class);mappings.put(CacheType.GENERIC, GenericCacheConfiguration.class.getName());mappings.put(CacheType.HAZELCAST, HazelcastCacheConfiguration.class.getName());mappings.put(CacheType.INFINISPAN, InfinispanCacheConfiguration.class.getName());mappings.put(CacheType.JCACHE, JCacheCacheConfiguration.class.getName());mappings.put(CacheType.COUCHBASE, CouchbaseCacheConfiguration.class.getName());mappings.put(CacheType.REDIS, RedisCacheConfiguration.class.getName());mappings.put(CacheType.CAFFEINE, CaffeineCacheConfiguration.class.getName());mappings.put(CacheType.CACHE2K, Cache2kCacheConfiguration.class.getName());mappings.put(CacheType.SIMPLE, SimpleCacheConfiguration.class.getName());mappings.put(CacheType.NONE, NoOpCacheConfiguration.class.getName());MAPPINGS = Collections.unmodifiableMap(mappings);}...代码...}

 缓存集成

依赖配置：

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-cache</artifactId>
</dependency>

加入依赖后，通过使用@EnableCaching注解来启用缓存功能。通过参数type指定要使用的缓存组件，以redis为示例：

spring:cache: type: redis

禁用缓存

spring:cache: type: none

 缓存类型type的值

• GENERIC: 通用缓存类型
• HAZELCAST: Hazelcast 缓存类型
• INFINISPAN: Infinispan 缓存类型
• JCACHE: JCache 缓存类型
• COUCHBASE: Couchbase 缓存类型
• REDIS: Redis 缓存类型
• CAFFEINE: Caffeine 缓存类型
• CACHE2K: Cache2k 缓存类型
• SIMPLE: 简单缓存类型
• NONE: 无缓存类型

redis缓存集成

在Spring Boot 2.7中使用@EnableCaching注解启用缓存功能时，如果你想使用Redis作为缓存存储，你需要在配置文件中指定Redis的相关配置。

application.properties或application.yml文件中添加以下配置：

spring:cache:type: redis # 指定缓存使用redisredis:host: 127.0.0.1 # Redis服务器地址database: 1 # Redis数据库索引（默认为0）port: 6379 # Redis服务器连接端口password: # Redis服务器连接密码（默认为空）

依赖配置：

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

 配置缓存管理器：

@Configuration
@EnableCaching
public class RedisTemplateConfiguration {/*** 默认过期时长，单位：秒*/@Getterprivate long expire = 60 * 60 * 24;
​@Beanpublic RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();redisTemplate.setKeySerializer(RedisSerializer.string());redisTemplate.setHashKeySerializer(RedisSerializer.string());redisTemplate.setValueSerializer(RedisSerializer.java());redisTemplate.setHashValueSerializer(RedisSerializer.java());redisTemplate.setConnectionFactory(factory);return redisTemplate;}
​@Beanpublic HashOperations<String, String, Object> hashOperations(RedisTemplate<String, Object> redisTemplate) {return redisTemplate.opsForHash();}
​@Beanpublic ValueOperations<String, String> valueOperations(RedisTemplate<String, String> redisTemplate) {return redisTemplate.opsForValue();}
​@Beanpublic ListOperations<String, Object> listOperations(RedisTemplate<String, Object> redisTemplate) {return redisTemplate.opsForList();}
​@Beanpublic SetOperations<String, Object> setOperations(RedisTemplate<String, Object> redisTemplate) {return redisTemplate.opsForSet();}
​@Beanpublic ZSetOperations<String, Object> zSetOperations(RedisTemplate<String, Object> redisTemplate) {return redisTemplate.opsForZSet();}
}