1 private void sendErrorToBrowser(HttpServletRequest request,HttpServletResponse response) throws IOException, ServletException{ 2     //请求类型 3     String requestType = request.getHeader("X-Requested-With"); 4      5     //ajax请求 6     if("XMLHttpRequest".equals(requestType)){ 7         response.sendError(HttpServletResponse.SC_UNAUTHORIZED); 8     }else{ 9         String path = request.getContextPath();10         String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";11         response.sendRedirect(basePath+"login.jsp");12     }13 }

$.ajax({    type : "POST",    url : url,    data : parma,    dataType : "json",    success : function(jsonObj) {            },    error : function(XMLHttpRequest, textStatus, errorThrown) {        if(401==XMLHttpRequest.status){            alert("请登陆后再操作!");            window.top.location.href = basepath + "login.jsp";        }else{            alert("计算失败,服务器发生错误,请联系系统管理员!");       }     },    beforeSend: function(){            }});