JSP部分：
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head>
<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"> <!--<link rel="stylesheet" type="text/css" href="styles.css">--></head><script language="javascript"> var xmlHttp; function createXMLHttpRequest() { if(window.ActiveXObject) { xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); } else { xmlHttp = new XMLHttpRequest(); } } function doHeadRequest(request, url) { requestType = request; createXMLHttpRequest(); xmlHttp.onreadystatechange = handleStateChange; xmlHttp.open("HEAD", url, true); xmlHttp.send(null); } function handleStateChange() { if(xmlHttp.readyState == 4) { if(requestType == "allResponseHeaders") { getAllResponseHeaders(); } else if(requestType == "lastModified") { getLastModified(); } else if(requestType == "isResourceAvailable") { getIsResourceAvailable(); } } } function getAllResponseHeaders() { alert(xmlHttp.getAllResponseHeaders()); } function getLastModified() { alert("Last Modified: " + xmlHttp.getResponseHeader("Last-Modified")); } function getIsResourceAvailable() { if(xmlHttp.status == 200) { alert("Successful response"); } else if(xmlHttp.status == 404) { alert("Resource is unavailable"); } else { alert("Unexpected response status: " + xmlHttp.status); } }</script><body> <h1> Reading Response Headers </h1> <a href="javascript:doHeadRequest('allResponseHeaders','readingResponseHeaders.xml');">Read All Response Headers</a> <br /> <a href="javascript:doHeadRequest('lastModified','readingResponseHeaders.xml');">Get Last Modified Date</a> <br /> <a href="javascript:doHeadRequest('isResourceAvailable','readingResponseHeaders.xml');">Read Available Resource</a> <br /> <a href="javascript:doHeadRequest('isResourceAvailable','not-available.xml');">Read Unavailable Resource</a>
</body>
</html>
readingResponseHeaders.xml部分（与jsp放在同一目录）
<?xml version="1.0" encoding="UTF-8"?><readingResponseHeaders></readingResponseHeaders>
