目錄

緩存支持

?緩存集成

redis緩存集成

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緩存支持

Spring 框架只提供抽象，不提供具體的緩存存儲，底層需要依賴第三方存儲組件，如果當前應用沒有注冊CacheManager 或者 CacheResolver 實例，Spring Boot 會按以下緩存組件的順序來檢測:

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

........

Spring Boot的自動配置類為：CacheAutoConfiguration，在 CacheAutoConfiguration 緩存自動配置類中引入了 CacheConfigurationImportSelector 配置選擇器：

@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;}}

該選擇器通過 CacheConfiqurations 緩存配置類來選擇對應緩存組件的配置類：

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);}...代碼...}

?緩存集成

依賴配置：

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

加入依賴后，通過使用@EnableCaching注解來啟用緩存功能。通過參數type指定要使用的緩存組件，以redis為示例：

spring:cache: type: redis

禁用緩存

spring:cache: type: none

?緩存類型type的值

• GENERIC: 通用緩存類型
• HAZELCAST: Hazelcast 緩存類型
• INFINISPAN: Infinispan 緩存類型
• JCACHE: JCache 緩存類型
• COUCHBASE: Couchbase 緩存類型
• REDIS: Redis 緩存類型
• CAFFEINE: Caffeine 緩存類型
• CACHE2K: Cache2k 緩存類型
• SIMPLE: 簡單緩存類型
• NONE: 無緩存類型

redis緩存集成

在Spring Boot 2.7中使用@EnableCaching注解啟用緩存功能時，如果你想使用Redis作為緩存存儲，你需要在配置文件中指定Redis的相關配置。

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

spring:cache:type: redis # 指定緩存使用redisredis:host: 127.0.0.1 # Redis服務器地址database: 1 # Redis數據庫索引（默認為0）port: 6379 # Redis服務器連接端口password: # Redis服務器連接密碼（默認為空）

依賴配置：

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

?配置緩存管理器：

@Configuration
@EnableCaching
public class RedisTemplateConfiguration {/*** 默認過期時長，單位：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();}
}