SpringCache

引入

自动配置

自定义配置

注解

@Cacheable

@CacheEvict

[sync = true](#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

XML 复制代码

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

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@EnableCaching开启缓存

自动配置

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CacheAutoConfiguration 依据缓存类型，自动配置缓存。

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CacheConfigurations 映射 相应的缓存配置

java 复制代码

    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);
    }

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

java 复制代码

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

        return (RedisCacheManager)this.customizerInvoker.customize(builder.build());
    }

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

java 复制代码

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

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redisCacheConfiguration 若为空，这采用默认配置

java 复制代码

    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

java 复制代码

@EnableCaching
@Configuration
public 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;
    }
}

R 复制代码

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

java 复制代码

@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

java 复制代码

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

SpringCache

SpringCache

引入

自动配置

自定义配置

注解

@Cacheable

@CacheEvict​​

sync = true

@CacheEvict