JS抓取网页title、keywords求助。

你可以参考如下的代码
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js" type="text/javascript"></script>
<script>
// jquery.xdomainajax.js  ------ from padolseyjQuery.ajax = (function(_ajax){    var protocol = location.protocol,
        hostname = location.hostname,
        exRegex = RegExp(protocol + '//' + hostname),
        YQL = 'http' + (/^https/.test(protocol)?'s':'') + '://query.yahooapis.com/v1/public/yql?callback=?',
        query = 'select * from html where url="{URL}" and xpath="*"';    function isExternal(url) {
        return !exRegex.test(url) && /:\/\//.test(url);
    }    return function(o) {        var url = o.url;        if ( /get/i.test(o.type) && !/json/i.test(o.dataType) && isExternal(url) ) {            // Manipulate options so that JSONP-x request is made to YQL            o.url = YQL;
            o.dataType = 'json';            o.data = {
                q: query.replace(
                    '{URL}',
                    url + (o.data ?
                        (/\?/.test(url) ? '&' : '?') + jQuery.param(o.data)
                    : '')
                ),
                format: 'xml'
            };            // Since it's a JSONP request
            // complete === success
            if (!o.success && o.complete) {
                o.success = o.complete;
                delete o.complete;
            }            o.success = (function(_success){
                return function(data) {                    if (_success) {
                        // Fake XHR callback.
                        _success.call(this, {
                            responseText: data.results[0]
                                // YQL screws with <script>s
                                // Get rid of them
                                //.replace(/<script[^>]+?\/>|<script(.|\s)*?\/script>/gi, '')
                        }, 'success');
                    }                };
            })(o.success);        }        return _ajax.apply(this, arguments);    };})(jQuery.ajax);$.ajax({
    url: 'http://www.sian.com/',
    type: 'GET',
    success: function(res) {
        var text = res.responseText;
        // then you can manipulate your text as you wish
        alert(text);
    }
});
</script>
</head>
<body>
</body>
</html>