public boolean preHandle(HttpServletRequest request, HttpServletResponse response,Object obj) throws Exception {
    
    //获取判定登陆的session是否存在
    String token = (String) request.getSession().getAttribute("token");
    String postId = (String) request.getSession().getAttribute("postId");
    if(token == null || token == ""){
      String XRequested =request.getHeader("X-Requested-With");
      if("XMLHttpRequest".equals(XRequested)){
        response.getWriter().write("IsAjax");
      }else{
        response.sendRedirect("/m-web/user/toLogin");
      }
      return false;
    }
    if(postId == null || postId == ""){
      String XRequested =request.getHeader("X-Requested-With");
      if("XMLHttpRequest".equals(XRequested)){
        response.getWriter().write("IsAjax");
      }else{
        response.sendRedirect("/m-web/user/toLogin");
      }
      return false;
    }
    return true;
  }

success:function(data){
  if(data == "IsAjax"){
    window.location.href="m-web/user/toLogin"
    return;
  }
}

　if ( isSuccess ) {// if no content
        if ( status === 204 || s.type === "HEAD" ) {
          statusText = "nocontent";

        // if not modified
        } else if ( status === 304 ) {
          statusText = "notmodified";

        // If we have data, let's convert it
        } else {
          statusText = response.state;
          success = response.data;
          error = response.error;
          isSuccess = !error;
          //解决ajax拦截问题
          var result = responses.text;
          if(result.indexOf("IsAjax")>=0){
            window.location.href="m-web/user/toLogin";
            return;
          }
        }
      }