User management, user authentication, access control, user profiles,
user accounts

Hi --

I'm trying to find a 3rd party module, library or other framework to
allow for user registration, authentication, basic ACLs etc for a new
J2EE-based web application. We don't need anything fancy, but it would
be nice to support basic modern self-registration (register, get an
email confirmation with an encrypted key, etc) as well as the ability
to assign users to groups / roles for ACL control, and the ability to
suspend accounts or turn them off. I've been looking at the facilities
provided by the Rails (Ruby) and Django (Python) frameworks and was
hoping to find something similar for Tomcat, especially given how long
J2EE has been around, but I've had a hard time finding anything.

The closest thing I've found is this post from 5 years ago (!):

http://groups.google.com/group/comp.lang.java.programmer/browse_thread/thread/bc
4f36008a0782b4/029d23012d75543e?hl=en&lnk=st&q=user+management+java+registration

But most of the links therein are fairly out of date. Any suggestions
on where to look?

Thanks in advance for your time,

Ramon