Mybe I'm wrong but I need a functionality and I'm just a biginner with Hibernate (1 day). I need to save the date and the user in every update of a Class with the Lyfecycle interface. No problem with the date but how with the user? I need to bind some property to the session! In this way i could use these to get some user information automatically end for every class.

There are other way?

You might want to consider the AuditInfo Custom Type pattern: http://www.hibernate.org/48.html

I extend the Threadlocal to store a class with the session and the user id, permissions etc that are related to the business transaction. It makes it similar if you like to the HTTPSession object. In this case the information is related to persistence rather Web requests.