Java based user authentication

Question

Can someone point me in the direction of a good Java library to use to handle basic user login/authentication.

I am looking for a competent I can integrate into a custom app to handle simple user/name password authentication and send account validation/password reset emails.

Answer 1

Filters would work: http://java.sun.com/products/servlet/Filters.html

Answer 2

Maybe you could use the JAAS (Java Authentication and Authorization Service). Look at the user guide and to get an overview of it look at the tutorials and simple programs of this guide.