stackoverflow_endpoint.java

public class EndpointsTask extends AsyncTask<Context, Integer, Long> {
  protected Long doInBackground(Context... contexts) {
  
    Userendpoint.Builder endpointBuilder = new Userendpoint.Builder(
            AndroidHttp.newCompatibleTransport(),
            new JacksonFactory(),
            new HttpRequestInitializer() {
                public void initialize(HttpRequest httpRequest) { }
            });
    Userendpoint endpoint = CloudEndpointUtils.updateBuilder(
            endpointBuilder).build();
  
    try {
        String username = "INSERT_USERNAME_HERE_DUDE!";
        User user = endpoint.getUser(username).execute();

        usernameTextView.setText(user.getUsername());
        locationTextView.setText(user.getLocation());
        ageTextView.setText(user.getAge());
        occupationTextView.setText(user.getOccupation());
        weightTextView.setText(user.getWeight());
        genderTextView.setText(user.getGender());
    } catch (Exception e) {
        e.printStackTrace();
    }
    return (long) 0;
  }
}

Recently I start an Android project with GAE and I think it is not good idea to use @entity classes from back-end part (for example User, Car and etc.) into Android app part. I guess it is good practice to separate the back-end and front-end functionality, so my questions are:

How we have to separate Entity classes (for example User, Car and etc.) from back-end (GAE) and front-end (Android app) ?

What response we have to return from back-end to android app when we want to get some Entity (for example User, Car and etc.) data and what arguments we have to pass from android app to back-end (some Endpoint)?