Spring RedirectAttributes在重定向后清除会话

Question

在我的Spring中，我使用RedirectAttributes在登录成功或失败后显示消息 我有一个SessionAttribute。我在两次设置SessionAttributes时首先是单击菜单 我将Object设置为SessionAttribute，第二个是登录成功后 我的问题是我在登录成功后设置的SessionAttribute如果我删除了，则无效 RedirectAttributes意味着它正常工作。

当我搜索时发现了这个

addFlashAttribute actually stores the attributes in a flashmap (which is internally maintained in the 
users session and removed once the next redirected request gets fulfilled)

当我调试它时，alwys显示默认值不会显示登录后设置的值。

这是登录

 @RequestMapping(value = "/sample-client", method = RequestMethod.POST)
    public String getClient(HttpServletRequest request, Model model, final RedirectAttributes redirectAttributes) {
        String userName = request.getParameter("userName");
        String password = request.getParameter("password");
       Client client = createClient(userName, password);
        if (client != null) {
            model.addAttribute("clientObject", client);
            redirectAttributes.addFlashAttribute("message", "Logined Successfully");
            return "redirect:" + "/sample/user";
        } else {
            redirectAttributes.addFlashAttribute("error", "true");
            return "redirect:" + "/sample/login";
        }
    }

after login 
 @RequestMapping(value = "/byName", method = RequestMethod.GET)
    public
    @ResponseBody
    String getUserByName(HttpServletRequest request, @ModelAttribute("clientObject") User user) {
        String firstName = request.getParameter("firstName");
        String lastName = request.getParameter("lastName");
        Integer page = Integer.parseInt(request.getParameter("page"));
        return sample.getUserSearchByName(user, firstName, lastName, page);
    }

当我在这里检查clientObject时，它会显示默认值。