XMLHttpRequest学习笔记一

通过XMLHttpRequest从服务端获取数据，并以表格方式进行展现，代码如下：
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

response.setHeader("Pragma","No-Cache");
response.setHeader("Cache-Control","No-Cache");
response.setHeader("Expires","0");
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'testxmlhttprequest.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>
  
  <body>
  	<!-- 请求服务器端的xml数据文件，并以表格方式进行展现 -->
    <script type="text/javascript">
    	
    	var xmlHttpRequest;
    	function createXMLHttpRequest() {
    		//support IE7+,firefox,Chrome,Opera,Safari and so on
    		if (window.XMLHttpRequest) {
    			xmlHttpRequest = new XMLHttpRequest();
    		} else {
    			//support IE6,IE5
    			//xmlHttpRequest = new ActiveXObject("Microsoft.XMLHTTP");
    			xmlHttpRequest = new ActiveXObject("MSXML2.XMLHTTP.3.0");
    		}
    		return xmlHttpRequest;
    	}
    	
    	//创建xmlhttp请求对象
    	xmlHttpRequest = createXMLHttpRequest();
    	xmlHttpRequest.open("GET","webpage/book.xml",false);
    	xmlHttpRequest.send();
    	
    	//
    	alert(xmlHttpRequest.responseText);
    	
    	var xmldom = xmlHttpRequest.responseXML;
    	//解析XMLDOM
    	var e_books = xmldom.getElementsByTagName("books")[0];
    	var e_book_array = e_books.childNodes;
    	document.writeln("<table border='1'>");
    	document.writeln("<tr><th>ID</th><th>Name</th><th>Author</th></tr>");
    	for(var i=0; i<e_book_array.length; i++) {
    		var e = e_book_array[i];
    		document.writeln("<tr><td>" + e.getElementsByTagName("id")[0].childNodes[0].nodeValue 
    		+ "</td><td>" + e.getElementsByTagName("name")[0].childNodes[0].nodeValue
    		+ "</td><td>" + e.getElementsByTagName("author")[0].childNodes[0].nodeValue 
    		+ "</td></tr>");
    	}
    	document.writeln("</table>");
    	
    </script>
  </body>
</html>