[转载]虾米网音乐真实地址解析 – zhoubo – 博客园.
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; 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; 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" ?> < 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 > < grade >-1</ grade > < artist > <![CDATA[Robert de Boron]]> </ artist > < location >4h%2Fxit7645F8219186pt3Ffi.%8%19%%%736733tA%3an2927%52569_5.p%2.meF2F52E5E9716m</ location > < ms ></ ms > </ 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。