UserPresenter.java

public class UserPresenter
        extends Presenter<UserPresenter.MyView, UserPresenter.MyProxy>
        implements UserUiHandlers {
    interface MyView extends View, HasUiHandlers<UserUiHandlers> {
        void displayUser(User user);
    }

    // ...
    
    private final PlaceManager placeManager;
    private final ResourceDelegate<UserApi> userApiResourceDelegate;

    @Inject
    UserPresenter(
            EventBus eventBus,
            MyView view,
            MyProxy proxy,
            PlaceManager placeManager,
            ResourceDelegate<UserApi> userApiResourceDelegate) {
        super(eventBus, view, proxy, RevealType.Root);

        this.placeManager = placeManager;
        this.userApiResourceDelegate = userApiResourceDelegate;

        getView().setUiHandlers(this);
    }

    @Override
    public void prepareFromRequest(PlaceRequest request) {
        int userId = parseUserIdFromPlaceRequest(request);

        userApiResourceDelegate.withCallback(new RestCallbackImpl<User>() {
            @Override
            public void onSuccess(User user) {
                getView().displayUser(user);
            }
        }).getUser(userId);
    }

    private int parseUserIdFromPlaceRequest(PlaceRequest placeRequest) {
        String idParameter = placeRequest.getParameter(NameTokens.PARAM_ID, "");
        return Integer.parseInt(idParameter);
    }

    // ...
}