I think I should rephrase this question ...

I have a rest service:

@Path("/")

@Produces("application/json")

public interface DataServiceResource {

    @GET

    @Path("/account/{param}")

    Account getAccount(@PathParam("param") String accountId);

}

I have another service which uses this DataService from inside of bean:

@Service(HelloRestService.class)

public class HelloRestServiceBean implements HelloRestService {

     @Override

    public Account getAccount(String accountId) {

       Account a = dataService.getAccount(accountId);

       return al;

    }

..

}

Obviously, DataService getAccount() returns the json representation of Account instance and ths line Account a = dataService.getAccount(accountId); in HelloRestServiceBean throws ClassCastException without any transform, I think.  I'd like to know how to write this transformer and where to put it??

Thanks