Logout when Session expired trigger NullPointerException

[Cesar M. Casasola]

I've been configured a handler for logout

<logout delete-cookies="true"  invalidate-session="true" 
            success-handler-ref="customLogoutSuccessHandler"/>

In method onLogoutSuccess of my handler class "CustomLogoutSuccessHandler" I've following

@Override
	public void onLogoutSuccess(HttpServletRequest request,
			HttpServletResponse response, Authentication authentication)
			throws IOException, ServletException{
		// TODO Auto-generated method stub
		System.out.println("logout");
		
		//code
	}

I used the authentication object, but when session expired this object is null, so that I can't use it .

In logout I need the user stored within the authentication object. When the session expired, How do I get it?