ajax应用
1.ajax的小例子（使用jquery类包）
<%@ 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 'addUser.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">
<script type="text/javascript" src="<%=basePath%>js/jquery-1.4.2.js"></script>
<script type="text/javascript">
function verify(){
var jqueryObj = $("#name");//$()不是EL表达式那样
var name = jqueryObj.val();//获取值
$.get('servlet/checkUser.do?name='+name,null,callback);
}
function callback(data){
var jqueryObj = $("#result");
jqueryObj.html(data);
}
</script>
</head>
<body>
<input type="text" name="name" id="name"/><br/>
<input type="text" name="password" onfocus="verify();"/><br/>
<div id="result"></div>
</body>
</html>
2.ajax的小例子（不使用jquery类包，使用GET）
<%@ 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 'addUser.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">
<script type="text/javascript">
var xmlHttp ;
if(window.XMLHttpRequest){
xmlHttp = new XMLHttpRequest();
if(xmlHttp.overrideMimeType){
xmlHttp.overrideMimeType('text/xml');
}
}else if(window.ActiveXObject){
var activeName = ['MSXML2.XMLHTTP','Microsoft.XMLHTTP'];
for(var i = 0 ; i < activeName.length ; i++){
try{
xmlHttp = new ActiveXObject(activeName[i]);
break;
}catch(e){}
}
}
if(!xmlHttp){
alert("请更新浏览器的版本!");
}
function verify(){
var name = document.getElementById("name").value;
xmlHttp.onreadystatechange = callback;
xmlHttp.open("GET","servlet/checkUser.do?name="+name,true);
xmlHttp.send(null);
}
function callback(){
var s = xmlHttp.responseText;
document.getElementById("result").innerHTML = s;
}
</script>
</head>
<body>
<input type="text" name="name" id="name" /> <br />
<input type="text" name="password" onfocus="verify();" />
<div id="result"></div>
</body>
</html>
3.ajax的小例子（不使用jquery类包，使用POST）
<%@ 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 'addUser.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">
<script type="text/javascript">
var xmlHttp ;
if(window.XMLHttpRequest){
xmlHttp = new XMLHttpRequest();
if(xmlHttp.overrideMimeType){
xmlHttp.overrideMimeType('text/xml');
}
}else if(window.ActiveXObject){
var activeName = ['MSXML2.XMLHTTP','Microsoft.XMLHTTP'];
for(var i = 0 ; i < activeName.length ; i++){
try{
xmlHttp = new ActiveXObject(activeName[i]);
break;
}catch(e){}
}
}
if(!xmlHttp){
alert("请更新浏览器的版本！");
}
function verify(){
var name = document.getElementById("name").value;
xmlHttp.onreadystatechange = callback;
xmlHttp.open("POST","servlet/checkUser.do",true);
xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xmlHttp.send("name="+name);
}
function callback(){
var responseText = xmlHttp.responseText;
document.getElementById("result").innerHTML = responseText;
}
</script>
</head>
<body>
<input type="text" name="name" id="name"/><br/>
<div id="result"></div>
</body>
</html>
<%@ 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 'addUser.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">
<script type="text/javascript" src="<%=basePath%>js/jquery-1.4.2.js"></script>
<script type="text/javascript">
function verify(){
var jqueryObj = $("#name");//$()不是EL表达式那样
var name = jqueryObj.val();//获取值
$.get('servlet/checkUser.do?name='+name,null,callback);
}
function callback(data){
var jqueryObj = $("#result");
jqueryObj.html(data);
}
</script>
</head>
<body>
<input type="text" name="name" id="name"/><br/>
<input type="text" name="password" onfocus="verify();"/><br/>
<div id="result"></div>
</body>
</html>
2.ajax的小例子（不使用jquery类包，使用GET）
<%@ 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 'addUser.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">
<script type="text/javascript">
var xmlHttp ;
if(window.XMLHttpRequest){
xmlHttp = new XMLHttpRequest();
if(xmlHttp.overrideMimeType){
xmlHttp.overrideMimeType('text/xml');
}
}else if(window.ActiveXObject){
var activeName = ['MSXML2.XMLHTTP','Microsoft.XMLHTTP'];
for(var i = 0 ; i < activeName.length ; i++){
try{
xmlHttp = new ActiveXObject(activeName[i]);
break;
}catch(e){}
}
}
if(!xmlHttp){
alert("请更新浏览器的版本!");
}
function verify(){
var name = document.getElementById("name").value;
xmlHttp.onreadystatechange = callback;
xmlHttp.open("GET","servlet/checkUser.do?name="+name,true);
xmlHttp.send(null);
}
function callback(){
var s = xmlHttp.responseText;
document.getElementById("result").innerHTML = s;
}
</script>
</head>
<body>
<input type="text" name="name" id="name" /> <br />
<input type="text" name="password" onfocus="verify();" />
<div id="result"></div>
</body>
</html>
3.ajax的小例子（不使用jquery类包，使用POST）
<%@ 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 'addUser.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">
<script type="text/javascript">
var xmlHttp ;
if(window.XMLHttpRequest){
xmlHttp = new XMLHttpRequest();
if(xmlHttp.overrideMimeType){
xmlHttp.overrideMimeType('text/xml');
}
}else if(window.ActiveXObject){
var activeName = ['MSXML2.XMLHTTP','Microsoft.XMLHTTP'];
for(var i = 0 ; i < activeName.length ; i++){
try{
xmlHttp = new ActiveXObject(activeName[i]);
break;
}catch(e){}
}
}
if(!xmlHttp){
alert("请更新浏览器的版本！");
}
function verify(){
var name = document.getElementById("name").value;
xmlHttp.onreadystatechange = callback;
xmlHttp.open("POST","servlet/checkUser.do",true);
xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xmlHttp.send("name="+name);
}
function callback(){
var responseText = xmlHttp.responseText;
document.getElementById("result").innerHTML = responseText;
}
</script>
</head>
<body>
<input type="text" name="name" id="name"/><br/>
<div id="result"></div>
</body>
</html>