通过RedisCacheManager自定义缓存序列化（适用通过注解缓存数据）

 1.Redis 注解默认序列化机制

1.Spring Boot整合Redis组件提供的缓存自动配置类RedisCacheConfiguration（org.springframework.boot.autoconfigure.cache）,

其内部是通过Redis连接工厂RedisConnectionFactory定义了一个缓存管理器RedisCacheManager；

同时定义RedisCacheManager时，也默认使用了JdkSerializationRedisSerializer序列化方式。

@Configuration(proxyBeanMethods = false)
@ConditionalOnClass(RedisConnectionFactory.class)
@AutoConfigureAfter(RedisAutoConfiguration.class)
@ConditionalOnBean(RedisConnectionFactory.class)
@ConditionalOnMissingBean(CacheManager.class)
@Conditional(CacheCondition.class)
class RedisCacheConfiguration {

	@Bean
	RedisCacheManager cacheManager(CacheProperties cacheProperties, CacheManagerCustomizers cacheManagerCustomizers,
			ObjectProvider<org.springframework.data.redis.cache.RedisCacheConfiguration> redisCacheConfiguration,
			ObjectProvider<RedisCacheManagerBuilderCustomizer> redisCacheManagerBuilderCustomizers,
			RedisConnectionFactory redisConnectionFactory, ResourceLoader resourceLoader) {
		RedisCacheManagerBuilder builder = RedisCacheManager.builder(redisConnectionFactory).cacheDefaults(
				determineConfiguration(cacheProperties, redisCacheConfiguration, resourceLoader.getClassLoader()));
		List<String> cacheNames = cacheProperties.getCacheNames();
		if (!cacheNames.isEmpty()) {
			builder.initialCacheNames(new LinkedHashSet<>(cacheNames));
		}
		if (cacheProperties.getRedis().isEnableStatistics()) {
			builder.enableStatistics();
		}
		redisCacheManagerBuilderCustomizers.orderedStream().forEach((customizer) -> customizer.customize(builder));
		return cacheManagerCustomizers.customize(builder.build());
	}

	private org.springframework.data.redis.cache.RedisCacheConfiguration determineConfiguration(
			CacheProperties cacheProperties,
			ObjectProvider<org.springframework.data.redis.cache.RedisCacheConfiguration> redisCacheConfiguration,
			ClassLoader classLoader) {
		return redisCacheConfiguration.getIfAvailable(() -> createConfiguration(cacheProperties, classLoader));
	}

	private org.springframework.data.redis.cache.RedisCacheConfiguration createConfiguration(
			CacheProperties cacheProperties, ClassLoader classLoader) {
		Redis redisProperties = 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.prefixCacheNameWith(redisProperties.getKeyPrefix());
		}
		if (!redisProperties.isCacheNullValues()) {
			config = config.disableCachingNullValues();
		}
		if (!redisProperties.isUseKeyPrefix()) {
			config = config.disableKeyPrefix();
		}
		return config;
	}

}

      2.如果想要使用自定义序列化方式的RedisCacheManager进行数据缓存操作，可以创建一个名为cacheManager的Bean组件，并在该组件中设置对应的序列化方式即可

2.自定义RedisCacheManager

@Bean
public RedisCacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {

    // 分别创建String和JSON格式序列化对象，对缓存数据key和value进行转换
    RedisSerializer<String>strSerializer = new StringRedisSerializer();
    Jackson2JsonRedisSerializer jacksonSeial = new Jackson2JsonRedisSerializer(Object.class);

    // 解决查询缓存转换异常的问题
    ObjectMapper om = new ObjectMapper();
    om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
    //过时om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
    //用下面的方法代替上面的方法
om.activateDefaultTyping(LaissezFaireSubTypeValidator.instance,ObjectMapper.DefaultTyping.NON_FINAL);
    jacksonSeial.setObjectMapper(om);
    // 定制缓存数据序列化方式及时效
    RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofDays(1))
                .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(strSerializer))
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jacksonSeial))
                .disableCachingNullValues();
    RedisCacheManager cacheManager = RedisCacheManager.builder(redisConnectionFactory).cacheDefaults(config).build();
    return cacheManager;
}

3.效果测试

项目启动成功后，通过浏览器访问http://localhost:8088/get/3，并重复刷新浏览器查看同一条数据信息 ,数据库只执行了一次SQL语句

缓存结果如下：