js+AJAX异步从优酷专辑中采集所有视频及信息

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html>
head>
title>JavaScipt AJAX 正则表达式 test/title>
script type="text/javascript" language="javascript">
function wrt(s){
subret.value = s + "\n" + subret.value;
//subret.value += "\n" + s;
}
var objRequest; //定义一个XML请求对象
var previd = "",nowid =0,listid = "",iscancel=false; //其他变量
function getlid(){
var listid = weburl.value.match(/playlist_show\/.*(?=id_(\d+)).*\.html$/i);
if(!listid){
return null;
} else {
return listid[1];
}
}
function retweb(){
if(objRequest.readyState == 4 objRequest.status == 200){
// 获得回调
var webstr = objRequest.responseText;
vid = webstr.match(/var\s+videoId\s*=\s*"(\d+)"\s*;/)[1];
vtitle = webstr.match(/title>(.+) - (.+) - 视频 - 优酷视频 - 在线观看( - )?\/title>/)[2];
wrt(nowid + ":" + vtitle + "=" + vid);
if(previd == vid) return;
previd = vid;
nowid += 1;
// 开始新循环
if(iscancel) return;
tstart();
} else {
//alert("回调失败！");
return;//"error: " + objRequest.statusText;
}
}
function getweb(u){
objRequest = new XMLHttpRequest(); //new ActiveXObject("Msxml2.XMLHTTP"); //IE56初始化XMLHTTP对象
objRequest.onreadystatechange = retweb; //异步回调方法
objRequest.open("GET",u,true);
objRequest.send(null);
}
function tstart(){
if(listid==""){
listid=getlid();
}
url = "http://v.youku.com/v_playlist/f" + listid + "o1p" + nowid + ".html";
getweb(url);
}

/script>
/head>
body>
input type="text" id="weburl" value="http://www.youku.com/playlist_show/id_2350764.html" style="width:640" />br />
textarea id="subret" readonly="readonly" style="width:640; height:360;">#star/textarea>
br/>
input type=button value="开始提取专辑" onclick="if(iscancel)iscancel=false;tstart();" />
input type=button value="清除文本" onclick="subret.value='';nowid =0;preid='';listid='';" />
input type=button value="暂停" onclick="iscancel=true;" />
/body>
/html>