Jersey JSON switching from camel case to underscores (snake case)

Question

I recently switched to jersey 2 ,. I went through the documentation/web and got to know how to convert response class to custom class using .readEntity(ClassName.class);

But I am stuck at using CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES naming strategy.

The current conversion fails as the response fields are with "_" and my POJO has Snake case .

Any help will be appreciated.

In jersey1 , I have been doing this :

MyResponse myResponse = client  
        .resource(url)
        .type(MediaType.APPLICATION_JSON)
        .accept(MediaType.APPLICATION_JSON)
        .post(RequestClass.class, request);

the same I am not able to achieve post jersey 2 : It gives compile time error when I as in above code :

I also tried :

MyResponse myResponse = client
        .target(getUrl())
        .request()
        .post(Entity.entity(request, MediaType.APPLICATION_JSON))
        .readEntity(MyResponse.class);

but it's not creating myResponse object , cause the response I get has Snake_case response but my POJO has camel case fields.

Answer 1

This is something that needs to be configured with the Jackson ObjectMapper. You can do this in a ContextResolver. Basically, you need something like

@Provider
public class MapperProvider implements ContextResolver<ObjectMapper> {
    final ObjectMapper mapper;

    public MapperProvider() {
        mapper = new ObjectMapper();
        mapper.setPropertyNamingStrategy(
                PropertyNamingStrategy.CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES);
    }

    @Override
    public ObjectMapper getContext(Class<?> cls) {
        return mapper;
    }
}

Then register with your client

client.register(MapperProvider.class);

If you need this support on the server also, then you will need to register it on the server too.