Facebook Connect for Java Web Application Login

Hello,

I've search around and I'm a bit confused as the best approach to allow facebook users access to my website using facebook connect. My web site is written in Java and I'm using Spring Security. Everything out there (spring social, facebook-java-api...etc) all seems somewhat implemented but doesn't provide examples to do the below, any ideas?  I just want to provide a sign up and login using facebook credentials.

-provide facebook connect button that lets user auth with their facebook credentials and then have it callback to a java service within my application so that I can create a user record in my database.