springboot2+redis +Jackson实现缓存序列

最近在升级Springboot从1.5到2.0的时候，发现redis缓存的配置方式有所变化。

1.5 的配置信息

    @Bean
    public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory connectionFactory) {
        RedisTemplate<Object, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(connectionFactory);

        //使用Jackson2JsonRedisSerializer来序列化和反序列化redis的value值
        Jackson2JsonRedisSerializer serializer = new Jackson2JsonRedisSerializer(Object.class);

        ObjectMapper mapper = new ObjectMapper();
        mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        mapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        serializer.setObjectMapper(mapper);

        template.setValueSerializer(serializer);
        //使用StringRedisSerializer来序列化和反序列化redis的key值
        template.setKeySerializer(new StringRedisSerializer());
        template.afterPropertiesSet();
        return template;
    }

如果直接使用的话，redis数据库中缓存的是字节，无法查看到具体信息。在查看配置文件的时候发现了这个提示，如下图所示：

image.png
这个在1.5的版本是可以直接注入的，出现这个问题，应该是版本有了新的的变化。翻看了新的官方文档，发现RedisCacheManager的初始化方式有所变化，不能将RedisTemplate直接注入，而采用了新的创建方式。
image.png

2.0配置

采用FastJson序列化问题

@Bean
public CacheManager cacheManager(RedisConnectionFactory connectionFactory) {
        //初始化一个RedisCacheWriter
        RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(connectionFactory);
        //设置CacheManager的值序列化方式为 fastJsonRedisSerializer,但其实RedisCacheConfiguration默认使用StringRedisSerializer序列化key，
        ClassLoader loader = this.getClass().getClassLoader();

        FastJsonRedisSerializer fastJsonRedisSerializer = new FastJsonRedisSerializer<>(loader.getClass());
        RedisSerializationContext.SerializationPair<Object> pair = RedisSerializationContext.SerializationPair.fromSerializer(fastJsonRedisSerializer);
        RedisCacheConfiguration defaultCacheConfig=RedisCacheConfiguration.defaultCacheConfig().serializeValuesWith(pair);
        RedisCacheManager cacheManager = new RedisCacheManager(redisCacheWriter, defaultCacheConfig);
        return cacheManager;
    }

 private static class FastJsonRedisSerializer<T> implements RedisSerializer<T> {
        private static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
        private Class<T> clazz;
        public FastJsonRedisSerializer(Class<T> clazz) {
            this.clazz = clazz;
        }

        @Override
        public byte[] serialize(T t) throws SerializationException {
            if (t == null) {
                return new byte[0];
            }
            return JSON.toJSONString(t, SerializerFeature.WriteClassName).getBytes(DEFAULT_CHARSET);
        }

        @Override
        public T deserialize(byte[] bytes) throws SerializationException {
            if (bytes == null || bytes.length <= 0) {
                return null;
            }
            String str = new String(bytes, DEFAULT_CHARSET);
            return (T) JSON.parseObject(str, clazz);
        }
    }

此方案在序列化的过程中没有问题，但是在反序列化的过程中，尤其是集合泛型转换的问题，需要设置autotype等比较麻烦，最后还是采用了原生的JackSon序列化方式。

JackSon

@Bean
public CacheManager cacheManager(RedisConnectionFactory connectionFactory) {
        //初始化一个RedisCacheWriter
        RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(connectionFactory);

        Jackson2JsonRedisSerializer serializer = new Jackson2JsonRedisSerializer(Object.class);

        RedisSerializationContext.SerializationPair<Object> pair = RedisSerializationContext.SerializationPair.fromSerializer(serializer);

        RedisCacheConfiguration defaultCacheConfig=RedisCacheConfiguration.defaultCacheConfig().serializeValuesWith(pair);

        return new RedisCacheManager(redisCacheWriter, defaultCacheConfig);
}