登錄超時給出提示跳到登錄頁面（ajax、導(dǎo)入、導(dǎo)出）

package com.lg.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.lg.func.MyFunc;
public class LoginFilter implements Filter{
public void destroy() {
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws ServletException, IOException {
HttpServletRequest request1=(HttpServletRequest)request;
HttpServletResponse response1=(HttpServletResponse)response;
chain.doFilter(request, response);//放行。讓其走到下個鏈或目標(biāo)資源中
String url=request1.getServletPath();
System.out.println("Demo1過濾前"+url);
MyFunc myFunc = new MyFunc(request1,response1);
System.out.println("Demo1過濾前"+url.startsWith("/index/"));
if(myFunc.checkLogin2()!url.startsWith("/index/")){
response1.sendRedirect("/index_login.html");
}
System.out.println("Demo1過濾后");
}
public void init(FilterConfig arg0) throws ServletException {
// TODO Auto-generated method stub
System.out.println("===========init========過濾后");
}
}

filter>
filter-name>Demo1Filter/filter-name>
filter-class>com.lg.filter.LoginFilter/filter-class>
/filter>
filter-mapping>
filter-name>Demo1Filter/filter-name>
url-pattern>*.jsp/url-pattern>
/filter-mapping> 

$.ajax({
type: "post",
url:"a.jsp",
async:false,//同步
data:{"name":"fdgh"}
success:function(msg){
//checkLogin2(msg)判斷是否登錄超時，超時返回false，跳到登錄頁面
if(checkLogin2(msg)){
var obj=eval('('+msg+')');
if(obj.result.indexOf("suc")>-1){
alert("成功");
}else{
alert("失敗");
}
}
});
//是否登錄超時，超時返回false，跳到登錄頁面
function checkLogin2(msg){
if(msg!=nullmsg.length>0){
if(msg.indexOf("DOCTYPE")>-1){
checkLogin();
return false;
}
}
return true;
}
function checkLogin(){
if(window.top != window.self){
top.asyncbox.alert('登錄超時，請重新登錄', '提示', function(action){ 
top.location.href='/login.jsp';
}); 
}else{
asyncbox.alert('登錄超時，請重新登錄', '提示', function(action){
window.location.href='/login.jsp';
}); 
}
}

if(checkLogin())return; 
//檢查登錄，session過期，或者未登錄，自動跳轉(zhuǎn)
public boolean checkLogin() throws IOException{
boolean result = false;
String html = "";
NativeObject u = SessionMng.getCurrentUser(request);//檢驗是否登錄超時
if (u == null){
html = "!DOCTYPE HTML PUBLIC '-//W3C//DTD HTML 4.01 Transitional//EN' 'http://www.w3.org/TR/html4/loose.dtd'>\n" +
"script type='text/javascript' src='/admin/js/jquery.min.js'>/script>\n" +
"script type='text/javascript' src='/admin/js/common.js'>/script>\n" + 
"script type='text/javascript' src='/admin/js/dialog/asyncbox.js'>/script>\n" + 
"script language=javascript>checkLogin();/script>\n";
response.getWriter().println(html); 
result = true;
}
return result;
}

if(!isLogin()){
response.getWriter().print("DOCTYPE");
return ;
}
//是否登錄
public boolean isLogin(){
NativeObject u = SessionMng.getCurrentUser(request);
if (u != null){
return true;
}else{
return false;
}
}

function export_excel(){ 
$.ajax({
type: "post",
url:"/admin/inc/checkLogin.jsp",
async:false,//同步
success:function(msg){
if(checkLogin2(msg)){
window.open("perfm_excel.jsp?"+$('#Form1').serialize());
}
}
}); 
login.jsp
%@ page contentType="text/html; charset=utf-8"%>
%
//========================當(dāng)前登陸用戶信息========================================
if(checkLogin())return;
%>