<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<style type="text/css">
#result{border:2px solid #999999;
background-color:#eeeeee;
}
</style>
<script type="text/javascript">
var xhr;
function getTime(){
try{
//先尝试使用标准方式创建（Firefox、Chrome都支持)
xhr=new XMLHttpRequest();
}catch(e){
//出现异常，意味着IE7之前版本，使用ActiveObject创建。
xhr=new ActiveXObject("Microsoft.XMLHttp");
}
//设置状态变化，回调函数;
xhr.onreadystatechange=callback;
//设置请求方式和URL
xhr.open("get","gettime");
//发送请求
xhr.send(null);
}
//状态变化的回调函数;
//判断请求完成，并且成功返回
function callback(){
if(xhr.readyState==4 && xhr.status==200){
var resDiv=document.getElementById("result");
var old=resDiv.innerHTML;
resDiv.innerHTML=old+xhr.responseText+"<br/>";
}
}
</script>
</head>
<body>
<input type="button" value='获取服务器时间' onclick='getTime()'/>
<div id='result'>
这里显示从服务器获取时间，多次点击按钮获取时间，不会刷新整个页面!~
</div>
</body>
</html>
Servlet代码;
resp.setContentType("text/html;charset=utf-8");
PrintWriter out=resp.getWriter();
Date date=new Date();
out.print(date);
out.flush();
out.close();