Logout when Session expired trigger NullPointerException

I've been configured a handler for logout

Code:

---

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

---

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

Code:

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@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?