Spring Integration Plugin for Vaadin 7

Hi Vaadin users,

I would like to know if its possible to us spring beans outside of the application class which extends UI ?

I would like to use in my LoginForm some Dao i need to register new users.
Here a example

public class LoginForm extends FormLayout
private UserService userService;

Ive try to do, but still got null pointer exception everytime. Did someone have solution ?

Thank You