虾米网音乐真实地址解析

  最近经常上虾米听歌,有些歌蛮好听的,昨天回上海准备下载一些音乐路上听,发现要用虾币购买,第一想法在chrome浏览器中按下F12,看Network中发出的报文,很轻松的找到了类似http://f3.xiami.net/78926/417559/08%201769939716_1875663.mp3这样的链接,这就是音乐的真实地址,可以直接下载下来。这里多说一句,很多人问怎么可以把在线的视频或者音乐下载到本地,网上也可以看到各式各样的回答,有用嗅探工具的,有从浏览器缓存找的,其实用chrome或者其他浏览器自带的抓包功能就很容易就能找到。

  上面是最简单的方法,但是需要很多手工操作,下面用程序的方式来解析,更重要的是提供一个这类问题的思路。

  首先来分析一下这首歌,地址是http://www.xiami.com/song/1769939716 从网页内容可以看到歌曲名字Rainbow Trees,演唱者 Robert de Boron,所属专辑 Diaspora,打开网页源代码注意到一些数字 1769939716,417599,78926.回头看看mp3的真实地址http://f3.xiami.net/78926/417559/08%201769939716_1875663.mp3,1769939716是歌曲ID,417599是所属专辑ID,78926是演唱者ID,发现这个url的构成 http://f3.xiami.net/演唱者ID/所属专辑ID/08%20歌曲ID_18655663.mp3.

这里还差一些东西08是什么?18655663是什么?%20我们知道是空格符,回到专辑页面http://www.xiami.com/album/417559发现这首歌Rainbow Trees是第八首歌,那18655663是什么?翻遍了chrome发出的所有报文,所有相关页面的源代码,没找到这个数字是什么意思。没办法,网上找了个反编译swf的软件,反编译了播放器的源代码,找到一些源代码

  下面的代码看起来像是获取歌曲位置的代码,再继续找到getLocation方法

var dataStr:* = evt.target.data;
            dataStr = dataStr.replace(" xmlns=\"http://xspf.org/ns/0/\"", "");
            var xmlData:* = new XML(dataStr);
            xmlData.ignoreWhitespace = true;
            uid = xmlData.uid;
            clearList = xmlData.clearlist;
            var songArr:* = xmlData.trackList.track;
            var tLoadArr:* = [];
            var backgroundStr:* = "";
            var firstSongId:* = 0;
            var addSongTmpArr:* = [];
            var oldDataArr:* = [];
            if (songArr[0] != undefined){
                for (i in songArr) {
                    tData = songArr[i];
                    songLocation = "";
                    thisLocation = tData.location;
                    if (thisLocation.indexOf("http://") < 0){
                        try {
                            songLocation = locationDec.getLocation(tData.location);
                        } catch(e) {
                        };
                    } else {
                        songLocation = thisLocation;
                    };

  

以下是getLocation方法

public function getLocation(_arg1:String):String{
            var _local10:*;
            var _local2:* = Number(_arg1.charAt(0));
            var _local3:* = _arg1.substring(1);
            var _local4:* = Math.floor((_local3.length / _local2));
            var _local5:* = (_local3.length % _local2);
            var _local6:* = new Array();
            var _local7:* = 0;
            while (_local7 < _local5) {
                if (_local6[_local7] == undefined){
                    _local6[_local7] = "";
                };
                _local6[_local7] = _local3.substr(((_local4 + 1) * _local7), (_local4 + 1));
                _local7++;
            };
            _local7 = _local5;
            while (_local7 < _local2) {
                _local6[_local7] = _local3.substr(((_local4 * (_local7 - _local5)) + ((_local4 + 1) * _local5)), _local4);
                _local7++;
            };
            var _local8:* = "";
            _local7 = 0;
            while (_local7 < _local6[0].length) {
                _local10 = 0;
                while (_local10 < _local6.length) {
                    _local8 = (_local8 + _local6[_local10].charAt(_local7));
                    _local10++;
                };
                _local7++;
            };
            _local8 = unescape(_local8);
            var _local9:* = "";
            _local7 = 0;
            while (_local7 < _local8.length) {
                if (_local8.charAt(_local7) == "^"){
                    _local9 = (_local9 + "0");
                } else {
                    _local9 = (_local9 + _local8.charAt(_local7));
                };
                _local7++;
            };
            _local9 = _local9.replace("+", " ");
            return (_local9);
        }

  这些代码看起来非常像获取地址的关键代码,沿着标黑的代码往上找到一个xml文件,并且这个xml文件里面应该有location这个标签,这时候找到这个xml文件很关键,这时候回到浏览器重新抓包,找到了这样一个链接http://www.xiami.com/song/playlist/id/1769939716(歌曲ID)/object_name/default/object_id/0。内容如下

<?xml version="1.0" encoding="utf-8"?>
<playlist version="1" xmlns="http://xspf.org/ns/0/">
<trackList>
<track>
<title><![CDATA[Rainbow Trees]]></title>
<song_id>1769939716</song_id>
<album_id>417559</album_id>
<album_name><![CDATA[Diaspora]]></album_name>
<object_id>1</object_id>
<object_name>default</object_name>
<insert_type>1</insert_type>
<background>http://img.xiami.com/res/player/bimg/bg-5.bak.jpg</background>
<grade>-1</grade>
<artist><![CDATA[Robert de Boron]]></artist>
<location>4h%2Fxit7645F8219186pt3Ffi.%8%19%%%736733tA%3an2927%52569_5.p%2.meF2F52E5E9716m</location>
<ms></ms>
<lyric>http://www.xiami.com/song/lyrictxt/id/1769939716</lyric>
<pic>http://img.xiami.com/images/album/img26/78926/4175591312340942_1.jpg</pic>
</track>
</trackList>
<uid>12390378</uid>
<type>default</type>
<type_id>1</type_id>
<clearlist></clearlist>
</playlist>

  里面找到了我想要的location标签中的内容。拿到源代码和location参数后就明白了,4h%2Fxit7645F8219186pt3Ffi.%8%19%%%736733tA%3an2927%52569_5.p%2.meF2F52E5E9716m这串字符串中,把第一个字符4拿出来,然后把剩余的字符串分为四部分,若能整除则每部分都一样长,若不能整除,则后余数个字符串少一个字符,这里拆开后为[h%2Fxit7645F8219186p, t3Ffi.%8%19%%%736733, tA%3an2927%52569_5., p%2.meF2F52E5E9716m],一共78个字符 4-78%4 = 2,因此数列为[20,20,19,19].然后从第一个字符串的第一个字符开始拼接,若把这个拆分后的字符串数组看成一个二维的字符数组,拼接方式为[0][0],[1][0],[2][0],[3][0],[4][0],[0][1],[1][1],[2][1],[3][1][4][1]... 拼完之后http%3A%2F%2Ff3.xiami.net%2F78926%2F417559%2F%5E8%252%5E1769939716_1875663.mp3,然后urldecode为http://f3.xiami.net/78926/417559/^8%2^1769939716_1875663.mp3,最后把^替换为字符0.

自己平时用java,把这段代码翻译成JAVA后。

public static String getLocation(String location) throws UnsupportedEncodingException {
		int _local10;
		int _local2 = Integer.parseInt(location.substring(0, 1));
		String _local3 = location.substring(1, location.length());
		double _local4 = Math.floor(_local3.length() / _local2);
		int _local5 = _local3.length() % _local2;
		String[] _local6 = new String[_local2];
		int _local7 = 0;
		while (_local7 < _local5) {
			if (_local6[_local7] == null) {
				_local6[_local7] = "";
			}
			_local6[_local7] = _local3.substring((((int) _local4 + 1) * _local7),
					(((int) _local4 + 1) * _local7) + ((int) _local4 + 1));
			_local7++;
		}
		_local7 = _local5;
		while (_local7 < _local2) {
			_local6[_local7] = _local3
					.substring((((int) _local4 * (_local7 - _local5)) + (((int) _local4 + 1) * _local5)),
							(((int) _local4 * (_local7 - _local5)) + (((int) _local4 + 1) * _local5))+(int) _local4);
			_local7++;
		}
		String _local8 = "";
		_local7 = 0;
		while (_local7 < ((String) _local6[0]).length()) {
			_local10 = 0;
			while (_local10 < _local6.length) {
				if (_local7 >= _local6[_local10].length()) {
					break;
				}
				_local8 = (_local8 + _local6[_local10].charAt(_local7));
				_local10++;
			}
			_local7++;
		}
		_local8 = URLDecoder.decode(_local8, "utf8");
		String _local9 = "";
		_local7 = 0;
		while (_local7 < _local8.length()) {
            if (_local8.charAt(_local7) == '^'){
                _local9 = (_local9 + "0");
            } else {
                _local9 = (_local9 + _local8.charAt(_local7));
            };
            _local7++;
        }
		_local9 = _local9.replace("+", " ");
		return _local9;
	}

  把location标签中的内容作为输入,输出结果就是我想要的mp3真实地址了。

  这里我提供以下我处理这类问题的思路,适用于视频真实地址,音乐真实地址的解析。首先是浏览器抓包,一般这种方式可以直接拿到真实地址,但是如果要做一个程序自动去抓这样还不行,需要知道这个地址是怎么生成的,比如土豆视频,通过一个请求获取一个xml,xml中就有视频地址,这种最简单。比如优酷的直接通过抓包看不出来是怎么算出来真实地址的,这时候需要反编译flash,然后把flash中的代码翻译成你自己想要的语言。

 

posted @ 2013-02-16 14:17  zhoubo  阅读(11734)  评论(26编辑  收藏