Spring data redis override default serializer

Question

I am trying to create a RedisTemplate bean which will have the updated value serializer to serialize an object in JSON format in redis.

@Configuration
class RedisConfig {

  @Bean(name = ["redisTemplate"])
  @Primary
  fun template(factory: RedisConnectionFactory): RedisTemplate<Any, Any> {
    val template = RedisTemplate<Any, Any>()
    template.connectionFactory = factory
    template.valueSerializer = Jackson2JsonRedisSerializer(Object::class.java)
    template.afterPropertiesSet()
    return template
  }
}

As per my understanding, spring should use the JSON serializer to serialize the object returned by the methods marked with Cacheable annotation. Despite this configuration, spring seems to be using the default Java serializer as this exception confirms this fact.

java.io.NotSerializableException: en.prateekj.vds.dto.Task
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
at java.util.ArrayList.writeObject(ArrayList.java:766)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:1128)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
at org.springframework.core.serializer.DefaultSerializer.serialize(DefaultSerializer.java:46)
at org.springframework.core.serializer.support.SerializingConverter.convert(SerializingConverter.java:63)
at org.springframework.core.serializer.support.SerializingConverter.convert(SerializingConverter.java:35)
at org.springframework.data.redis.serializer.JdkSerializationRedisSerializer.serialize(JdkSerializationRedisSerializer.java:94)
at org.springframework.data.redis.serializer.DefaultRedisElementWriter.write(DefaultRedisElementWriter.java:43)
at org.springframework.data.redis.serializer.RedisSerializationContext$SerializationPair.write(RedisSerializationContext.java:219)
at org.springframework.data.redis.cache.RedisCache.serializeCacheValue(RedisCache.java:238)
at org.springframework.data.redis.cache.RedisCache.put(RedisCache.java:144)
at org.springframework.cache.interceptor.AbstractCacheInvoker.doPut(AbstractCacheInvoker.java:87)
at org.springframework.cache.interceptor.CacheAspectSupport$CachePutRequest.apply(CacheAspectSupport.java:770)
at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:398)
at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:314)
at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:61)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689)

Am I missing any configuration or something by which spring is not able to determine what RedisTemplate to use?

Answer 1

You have probably solved it meanwhile, but for further answer seekers.

According to spring data redis reference:

By default, RedisCache and RedisTemplate are configured to use Java native serialization.

From stacktrace I can see that you are actually using Redis for caching, so you need to configure RedisCache and not RedisTemplate. RedisCache is not picking up your @Bean because it is not using RedisTemplate internally.

Example how you can do it in Java:

    @EnableCaching
    @Configuration
    public class CacheConfig {

        @Bean
        @Primary
        public RedisCacheConfiguration defaultCacheConfig(ObjectMapper objectMapper) {
            return RedisCacheConfiguration.defaultCacheConfig()
                .serializeKeysWith(SerializationPair.fromSerializer(new StringRedisSerializer()))
                .serializeValuesWith(SerializationPair.fromSerializer(new GenericJackson2JsonRedisSerializer(objectMapper)));
        }

    }