GAEでユーザ管理

GAEでAdministratorしか使えないページを作る場合．

public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        UserService userService = UserServiceFactory.getUserService();
        String thisURL = request.getRequestURI();
        if (request.getUserPrincipal() != null && userService.isUserAdmin()) {
         String urlLogout = userService.createLogoutURL(thisURL);
         request.setAttribute("urlLogout", urlLogout);

         RequestDispatcher rd = request.getRequestDispatcher(jsp).forward(request, response);
        } else {
            response.getWriter().println("<p>
Please <a href=\"" +userService.createLoginURL(thisURL) +"\">sign in</a>.</p>");
        }

 }

これで，jsp側で

<%
String urlLogout = (String)request.getAttribute("urlLogout");
%>
・・・
<a href="<%=urlLogout%>">ログアウト</a>

としてあげればOk．