Check out OWASP's ESAPI (Enterprise Security API).
ESAPI (The OWASP Enterprise Security API) is a free, open source, web application security control library that makes it easier for programmers to write lower-risk applications. The ESAPI libraries are designed to make it easier for programmers to retrofit security into existing applications. The ESAPI libraries also serve as a solid foundation for new development.
While it is ported to several languages and frameworks, it started as a Java EE project. It's a very large and flexible framework, should meet most of your needs.
And as far as authentication and user management goes, strongly consider using OpenID (or something like that), so you dont have to manage it at all. Depending on your usecases and userbase, this can be a huge benefit, to you AND your users.