<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
window.onload = function() {
//1. 获取 a 节点， 为其添加onclick 响应函数
document.getElementsByTagName("a")[0].onclick = function() {
//3.创建一个XMLHttpRequest 对象
var request = new XMLHttpRequest();
//4.准备发送请求的数据：url;
var url = this.href;
var method = "GET";
//5.调用XMLHttpRequest 对象的open 方法
request.open(method, url);
//6.调用XMLHttpRequest 对象的send 方法
request.send(null);
//7.为 XMLHttpRequest 对象添加onreadystatechange 响应函数
request.onreadystatechange = function() {
//8.判断响应是否完成 ，XMLHttpRequest对象的readyState 属性值为4 的时候
if (request.readyState == 4) {
//9.再判断响应是否可用：XMLHttpRequest 对象status 属性值为200
if (request.status == 200 || request.status==304) {
alert(request.responseText);
}
}
}
//2.取消a节点的默认行为
return false;
}
}
</script>
</head>
<body>
<a href="hallow.txt">hallow</a>
</body>
</html>