Different JSON output when using custom json serializer in Spring Data Rest

Question

After adding a custom Jackson serializer based on the official documenation I\'ve observed a slightly different json output format.

This example is base

Answer 1

This is not a bug of Spring Data Rest it is actually the normal behaviour of the Jackson Serializer. Whenever you use the @JsonUnwrapped Annotation (as the Resource content field does) together with a custom Serializer the Jackson Serializer will explicitly write the field name (in this case content). Have a look at the UnwrappingBeanPropertyWriter for more details. Anyhow you have been on the right track using the UnwrappingBeanSerializer but the setup is slightly different then the usual Serializer registration. The following example should fix your problem:

@Override
protected void configureJacksonObjectMapper(ObjectMapper objectMapper) {
    mapper.registerModule(new Module() {
        @Override
        public String getModuleName() {
            return "my.module";
        }

        @Override
        public Version version() {
            return Version.unknownVersion();
        }

        @Override
        public void setupModule(SetupContext context) {

            context.addBeanSerializerModifier(new BeanSerializerModifier() {
                @Override
                public JsonSerializer modifySerializer(SerializationConfig config, BeanDescription beanDesc, JsonSerializer serializer) {
                    if(beanDesc.getBeanClass().equals(Order.class)) {
                        return new UnwrappingOrderSerializer((BeanSerializerBase) serializer, NameTransformer.NOP);
                    }
                    return serializer;
                }
            });
        }
    });
}

public class UnwrappingOrderSerializer extends UnwrappingBeanSerializer {
    public UnwrappingBarSerializer(BeanSerializerBase src, NameTransformer transformer) {
        super(src, transformer);
    }

    @Override
    public JsonSerializer