Java Development Tools

I'm developing an application under JDeveloper 11.1.1.3.0 (since the targetted WLS is 10.3.3)

Using ADF security, I use a specific login page with the code associated with the submit button is the following :

      int authSuccess =
        ServletAuthentication.login(strUsername, strPassword, request,
                                    response);
      if (ServletAuthentication.AUTHENTICATED == authSuccess) {
        NavigationHandler nvHndlr =
          FacesContext.getCurrentInstance().getApplication().getNavigationHandler();
        nvHndlr.handleNavigation(FacesContext.getCurrentInstance(), null,
                                 "home");
      }

When clicking on the logout button of the homepage, this navigates to an url view returned by a bean function with this code :

    FacesContext ctx = FacesContext.getCurrentInstance();
    ExternalContext ectx = ctx.getExternalContext();
    HttpServletRequest request = null;
    request = (HttpServletRequest)ectx.getRequest();
    boolean logout;
    try {
      logout = ServletAuthentication.logout(request);
    } catch (Exception e) {
      System.out.println("Exception: " + e);
    }
    strUrl =
        ectx.getRequestContextPath() + "/adfAuthentication?logout=true&end_url=" +
        ectx.getRequestContextPath() + "/faces/loginpage";
    return strUrl;

But doing this the session is not invalidated.
If i use ServletAuthentication.invalidateAll(request); or session.invalidate(); call, then the navigation fails.

How can I force invalidate and login ?