I can check validation on properties of beans with the Validator Framework.
In the login page,
I check if the user enters his user-ID and password.
I put ser-ID and password as required,
that works greats, if he don't enter login, message is displayed, also for password.
Now I am checking if the user-ID and the associated password are valid in my Database,
to see if he is a valid registered user.
When he submits the form (user-ID and password fields), I go check in DB,
how should I handle the errors now and the display of them ?