Ajax登陆使用Spring Security缓存跳转到登陆前的链接

if (savedRequest != null) {
  // 逻辑代码
 }

String url = savedRequest.getRedirectUrl();

Map json = new HashMap<String, Object>();
   json.put("code", 0);
   json.put("message", "操作成功");
   json.put("url", url);

response.getWriter().write(mapper.writeValueAsString(ResponseBo.ok(messsage, url)));

@Override
 public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response, Authentication authentication) throws IOException, ServletException {
  // 不管请求哪个页面，登陆成功后仅打开指定页面index
//  redirectStrategy.sendRedirect(request, response, "/index");
  // 获取缓存
  SavedRequest savedRequest = requestCache.getRequest(request, response);
  // 设置响应格式和编码
  response.setContentType(FebsConstant.JSON_UTF8);
  
  // 缓存非空判断
  if (savedRequest != null) {
   // 跳转到之前引发跳转的url
   String url = savedRequest.getRedirectUrl();
   
   String messsage = "成功";
   // 准备json
   Map json = new HashMap<String, Object>();
   json.put("code", 0);
   json.put("message", "操作成功");
   json.put("url", url);

   Object jsons = ResponseBo.ok(messsage, url);
   response.getWriter().write(mapper.writeValueAsString(ResponseBo.ok(messsage, url)));
  } else {
   // 这个是没有缓存，直接跳转到默认ajax默认的页面
   response.getWriter().write(mapper.writeValueAsString(ResponseBo.ok()));
  }
 }

$.ajax(
  {
   type: "post",
   url: "/login",
   // 登陆表单数据序列化
   data: $form.serialize(),
   dataType: "json",
   error: function (data, type, err) {
    if (data.responseJSON != undefined) {
     console.log(data.responseJSON.error != undefined);
     console.log(JSON.stringify(data.responseJSON.error));
     $MB.n_danger("error：" + JSON.stringify(data.responseJSON.error));
    }
   },
   success: function (data) {
    console.log(JSON.stringify(data));
    alert(JSON.stringify(data));

    if (data.code == 0) {
     // 如果有url，则跳转该url
     if (data.url != undefined) {
      $form[0].reset();
      window.location.href = data.url;
     } else {
      // 重置表单的输入框内容
      $form[0].reset();
      window.location.href = '/index';
      // $form.attr("action", '/index');
     }

    } else {
     // if (r.msg !== '验证码不能为空！') reloadCode();
     console.log(data.message);
    }
   },
  }
 );