code: protected void handleLoginEvent(LoginEvent event)
      {
          ApplicationSessionInitializer asi = getApplicationSessionInitializer();
          if (asi != null)
          {
              asi.initializeUser();
              Map<String, Object> userAttributes = asi.getUserAttributes();
              if (userAttributes != null)
              {
                  setUserAttributes(userAttributes);
              }
          }
          Authentication auth = (Authentication) event.getSource();
          propertyChangeSupport.firePropertyChange(USER, null, auth);
      }
docs: When a correct login occurs, read all relevant userinformation into
  session.
  
  @param event
  the loginEvent that triggered this handler.