Can any one please provide BlazeDS working with user identification?

Question

Generaly all I want is to create simple Wiki like flex app using BlazeDS and Hibernate (like one provided in Enverse (part of Hibernate ) presentation Data Versioning and Envers Adam Warski JBoss / Red Hat)... Jeneraly I get how to do most of stuff to create service model but this is what I do not get:

public class WikiListener implements RevisionListener {
    public void newRevision(Object revEntity) {
        WikiRevision wikiRev = (WikiRevision)revEntity;
        User currentUser = (User)Component.getInstance("currentUser");
        wikiRev.setModifiedBy(currentUser);
    }
}

how to create classes for managing stuff like

User currentUser = (User)Component.getInstance("currentUser");

in blaze ?