本文实例讲述了ajax遍历xml文档的方法。分享给大家供大家参考。具体分析如下：
XMLHttpRequest对象提供了两个可以用来访问服务器响应的属性。第一个属性responseText将响应提供为一个串，第二个属性 responseXML将响应提供为一个XML对象。一些简单的用例就很适合按简单文本来获取响应，如将响应显示在警告框中，或者响应只是指示成功还是失 败的词
前面<ajax小结>中的例子是从XMLHttpRequest对象获取服务器响应，并使用XMLHttpRequest对象的responseText属性将响应获取为文本。
这次我们来使用XMLHttpRequest对象的responseXML属性，将结果获取为XML文档.这样一来，我们就可以使用W3C DOM方法来遍历XML文档。(前面文章或多或少讲过些DOM,在此不重复)
OK,下面来看例子.
首先还是一段XML文档代码(parseXML.xml)如下:
parseXML.xml如下：
<?xml version="1.0" encoding="UTF-8"?> <states> <north> <state>Minnesota</state> <state>Iowa</state> <state>North Dakota</state> </north> <south> <state>Texas</state> <state>Oklahoma</state> <state>Louisiana</state> </south> <east> <state>New York</state> <state>North Carolina</state> <state>Massachusetts</state> </east> <west> <state>California</state> <state>Oregon</state> <state>Nevada</state> </west> </states>
MyJsp.jsp如下：
<%@ 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 'MyJsp.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">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<script type="text/javascript">
var flg=false;
var requestType = "";
//得到XMLHttpRequest对象
function newXMLHttpRequest() {
var xmlreq = false;
if (window.XMLHttpRequest) {
xmlreq = new XMLHttpRequest();
} else if (window.ActiveXObject) {
try {
xmlreq = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e1) {
try {
xmlreq = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e2) {}
}
}
return xmlreq;
}
function startRequest(requestedList){
requestType=requestedList;
flg=newXMLHttpRequest();
//当XMLHttpRequest对象在请求过程中间状态改变的时候
//回来调用handleStateChange方法
flg.onreadystatechange = handleStateChange;
flg.open("GET", "parseXML.xml", true);
flg.send(null);
}
//处理函数
function handleStateChange(){
if(flg.readyState==4){
if(flg.status==200){
if(requestType=="north"){
listNorthStates();
}else if(requestType=="all"){
listAllStates();
}if(requestType=="south"){
listSouthStates();
}
}
}
}
//用于显示NorthStates方法
function listNorthStates(){
var xmlDoc=flg.responseXML;
var northNode=xmlDoc.getElementsByTagName("north")[0];
var northStates=northNode.getElementsByTagName("state");
outputList("North States",northStates);
}
//用于显示SouthStates方法
function listSouthStates(){
var xmlDoc=flg.responseXML;
var SouthNode=xmlDoc.getElementsByTagName("south")[0];
var SouthStates=SouthNode.getElementsByTagName("state");
outputList("South States",SouthStates);
}
//用于显示AllStates方法
function listAllStates(){
var xmlDoc=flg.responseXML;
var allStates=xmlDoc.getElementsByTagName("state");
outputList("All States in Document", allStates);
}
//输出元素并显示于提示框中
function outputList(title,states){
var out=title;
var currState=null;
for(var i=0;i<states.length;i++){
currState=states;
out=out+"\n-"+currState.childNodes[0].nodeValue;
}
alert(out);
}
</script>
<body>
<form action="#">
<input type="button" value="View All Listed States"
onclick="startRequest('all');"/><br>
<input type="button" value="View All Listed Northern States"
onclick="startRequest('north');"/><br>
<input type="button" value="View All Listed Southern States"
onclick="startRequest('south');"/>
</form>
</body>
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