Save POJO with big Map inside via Spring Data repository leads to StackOverflowError

Question

Generally: i'm reading serialized object (as JSONs) from Kafka Stream and trying to save it to Redis using Spring Data repository.
After a two calls (objects has not been saved to Redis) to repository.save() i get StackOverFlowError:

Exception in thread "processOffers-applicationId-1c24ef63-baae-47b9-beb7-5e6517736bc4-StreamThread-1" java.lang.StackOverflowError
at org.springframework.data.util.Lazy.get(Lazy.java:94)
at org.springframework.data.mapping.model.AnnotationBasedPersistentProperty.usePropertyAccess(AnnotationBasedPersistentProperty.java:277)
at org.springframework.data.mapping.model.BeanWrapper.getProperty(BeanWrapper.java:134)
at org.springframework.data.mapping.model.BeanWrapper.getProperty(BeanWrapper.java:115)
at org.springframework.data.redis.core.convert.MappingRedisConverter.lambda$writeInternal$2(MappingRedisConverter.java:601)
at org.springframework.data.mapping.model.BasicPersistentEntity.doWithProperties(BasicPersistentEntity.java:353)
at org.springframework.data.redis.core.convert.MappingRedisConverter.writeInternal(MappingRedisConverter.java:597)
at org.springframework.data.redis.core.convert.MappingRedisConverter.lambda$writeInternal$2(MappingRedisConverter.java:639)

Serialized POJO look like this:

@Data
@With
@NoArgsConstructor
@AllArgsConstructor
@RedisHash("students")
public class Student {
    @Id
    @JsonProperty("student_id")
    private long id;

    @JsonProperty("entities")
    private Map<String, Object> entities = new HashMap<>();
}

Map entities contains 100+ Entries, with nested maps (objects).
Interesting part: if i make map empty everything works fine and data instantly saved to Redis.

Corresponding repository for POJO:

@Repository
public interface StudentRepository extends CrudRepository<Student, Long> {
}

Also, i've defined RedisCustomConversion for Long id field:

@Component
@ReadingConverter
public class BytesToLongConverter implements Converter<byte[], Long> {
    @Override
    public Long convert(final byte[] source) {
        ByteBuffer buffer = ByteBuffer.allocate(Long.BYTES);
        buffer.put(source);
        buffer.flip();
        return buffer.getLong();
    }
}

@Component
@WritingConverter
public class LongToBytesConverter implements Converter<Long, byte[]> {
    @Override
    public byte[] convert(final Long source) {
        ByteBuffer buffer = ByteBuffer.allocate(Long.BYTES);
        buffer.putLong(source);
        return buffer.array();
    }
}

Redis configuration class looks like this:

@Configuration
@EnableRedisRepositories
public class RedisConfiguration {
    @Bean
    @Primary
    public RedisProperties redisProperties() {
        return new RedisProperties();
    }

    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        var config = new RedisStandaloneConfiguration();
        var props = redisProperties();
        config.setHostName(props.getHost());
        config.setPort(props.getPort());
        return new JedisConnectionFactory(config);
    }

    @Bean
    public RedisTemplate<String, Object> redisTemplate() {
        var template = new RedisTemplate<String, Object>();
        template.setConnectionFactory(redisConnectionFactory());
        template.setDefaultSerializer(new GenericJackson2JsonRedisSerializer());
        return template;
    }

    @Bean
    public RedisCustomConversions redisCustomConversions(LongToBytesConverter longToBytes,
                                                         BytesToLongConverter bytesToLong) {
        return new RedisCustomConversions(Arrays.asList(longToBytes, bytesToLong));
    }
}

UPD: I've found this issue on Spring Data Redis Jira, but the resolution set as "Fixed", so it's seems strange to me.

Answer 1

I've defined custom WritingConverter and ReadingConverter for my inner map in POJO using GenericJackson2JsonRedisSerializer and everything worked out! Code:

@Component
@WritingConverter
public class FieldsToBytesConverter implements Converter<Map<String, Object>, byte[]> {
    private final RedisSerializer serializer;

    public FieldsToBytesConverter() {
        serializer = new GenericJackson2JsonRedisSerializer();
    }

    @Override
    public byte[] convert(Map<String, Object> value) {
        return serializer.serialize(value);
    }
}

@Component
@ReadingConverter
public class BytesToFieldsConverter implements Converter<byte[], Map<String, Object>> {
    private final GenericJackson2JsonRedisSerializer serializer;

    public BytesToFieldsConverter() {
        serializer = new GenericJackson2JsonRedisSerializer();
    }

    @Override
    public Map<String, Object> convert(byte[] value) {
        return (Map<String, Object>) serializer.deserialize(value);
    }
}