JacksonConfig.java

    private static final ObjectMapper objectMapper = new ObjectMapper()
            .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
            .configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false).setSerializationInclusion(Include.NON_NULL)
            .configure(SerializationFeature.WRITE_NULL_MAP_VALUES, false);

    static {
        objectMapper.getSerializerProvider().setNullKeySerializer(new NullKeySeriliazer());
        objectMapper.setVisibility(objectMapper.getSerializationConfig().getDefaultVisibilityChecker()
                .withFieldVisibility(JsonAutoDetect.Visibility.ANY).withGetterVisibility(JsonAutoDetect.Visibility.NONE)
                .withSetterVisibility(JsonAutoDetect.Visibility.NONE)
                .withCreatorVisibility(JsonAutoDetect.Visibility.NONE));
    }