MP3文件的ID3v1信息储存的结构可以参考http://www.cnblogs.com/ycoe/archive/2006/08/14/476759.html
本类是自己写的一个操作MP3文件ID3v1信息的类
package com.xu.obj;import java.io.File;import java.io.FileNotFoundException;import java.io.IOException;import java.io.RandomAccessFile;import java.io.UnsupportedEncodingException;import com.xu.exception.MusicInfoOptException;
public class ID3v1Info {
final public static int LENGTH = 128;
private byte[] TAG = new byte[] { 'T', 'A', 'G' };
final public static String ENCODE = "GB2312"; final public static int TITLE_START = 3; final public static int TITLE_LENGTH = 30; final public static int ARTIST_START = 33; final public static int ARTIST_LENGTH = 30; final public static int ALBUM_START = 63; final public static int ALBUM_LENGTH = 30; final public static int YEAR_START = 93; final public static int YEAR_LENGTH = 4; final public static int COMMENTS_START = 97; final public static int COMMENTS_LENGTH_28 = 28; final public static int COMMENTS_LENGTH_30 = 30; final public static int RESERVED = 125; final public static int TRACK = 126; final public static int GENRE = 127; private File file = null; private String title = ""; private String artist = ""; private String album = ""; private String year = ""; private String comment = ""; private String track = ""; private String genre = ""; public String getAlbum() { return album;
} public void setAlbum(String album) { this.album = album; } public String getComment() { return comment; } public void setComment(String comment) { this.comment = comment; } public File getFile() { return file; } public void setFile(File file) throws MusicInfoOptException{ if ("mp3".endsWith(file.getName().toLowerCase())) { throw new MusicInfoOptException("不是MP３文件！"); } this.file = file; this.getMusicInfo(); } public String getGenre() { return genre; } public void setGenre(String genre) { this.genre = genre; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getArtist() { return artist; } public void setArtist(String artist) { this.artist = artist; } public byte[] getTAG() { return TAG; } public void setTAG(byte[] tag) { TAG = tag; } public String getTrack() { return track; } public void setTrack(String track) { this.track = track; } public String getYear() { return year; } public void setYear(String year) { this.year = year; } public ID3v1Info(File file) throws MusicInfoOptException { if ("mp3".endsWith(file.getName().toLowerCase())) throw new MusicInfoOptException("不是MP３文件！"); this.file = file; this.getMusicInfo(); } /** * 从音乐文件里取得3v1版本的音乐信息 * * @throws MusicInfoOptException */ private void getMusicInfo() throws MusicInfoOptException { byte[] buf = new byte[LENGTH]; RandomAccessFile raf; try { raf = new RandomAccessFile(this.file, "r"); } catch (FileNotFoundException e) { throw new MusicInfoOptException("没有此文件！"); } try { raf.seek(raf.length() - LENGTH); raf.readFully(buf); raf.read(buf); } catch (IOException e) { throw new MusicInfoOptException(e.getMessage()); } try { if (!"TAG".equals(new String(buf, 0, 3, ENCODE))) throw new MusicInfoOptException("音乐文件中不包含3v1版本信息！"); this.setAlbum(new String(buf, ALBUM_START, ALBUM_LENGTH, ENCODE) .trim()); this.setComment(new String(buf, COMMENTS_START, COMMENTS_LENGTH_28, ENCODE).trim()); this.setGenre(new String(buf, GENRE, 1, ENCODE).trim()); this.setTitle(new String(buf, TITLE_START, TITLE_LENGTH, ENCODE) .trim()); this.setArtist(new String(buf, ARTIST_START, ARTIST_LENGTH, ENCODE) .trim()); this.setTrack(new String(buf, TRACK, 1, ENCODE).trim()); this.setYear(new String(buf, YEAR_START, YEAR_LENGTH, ENCODE) .trim()); } catch (UnsupportedEncodingException e) { throw new MusicInfoOptException(e.getMessage()); } try { raf.close(); } catch (IOException e) { throw new MusicInfoOptException(e.getMessage()); } } /** * 将3v1信息保存进音乐文件中 * * @throws MusicInfoOptException * * @throws Exception */ public void save(MusicInfo musicInfo) throws MusicInfoOptException { this.setAlbum(musicInfo.getAlbum()); this.setArtist(musicInfo.getArtist()); this.setComment(musicInfo.getComment()); this.setGenre(musicInfo.getGenre()); this.setTitle(musicInfo.getTitle()); this.setTrack(musicInfo.getTrack()); this.setYear(musicInfo.getYear()); RandomAccessFile raf = null; byte[] buf = new byte[LENGTH]; try { raf = new RandomAccessFile(this.file, "rwd"); } catch (FileNotFoundException e) { throw new MusicInfoOptException(e.getMessage()); } try { raf.seek(raf.length() - LENGTH);// raf.readFully(buf); raf.read(buf); } catch (IOException e) { throw new MusicInfoOptException(e.getMessage()); } boolean have3v1 = true;// 是否有3v1信息 try { if (!"TAG".equals(new String(buf, 0, 3, ENCODE))) { // 如果没有3v1信息 buf = new byte[LENGTH]; buf[0] = 'T'; buf[1] = 'A'; buf[2] = 'G'; have3v1 = false; } } catch (UnsupportedEncodingException e) { throw new MusicInfoOptException(e.getMessage()); } // 将信息填充到buf中去 int count = 0;// 写入字符长度 // 写入歌手名 count = artist.getBytes().length; if (count > ARTIST_LENGTH) count = ARTIST_LENGTH; for (int ii = 0; ii < count; ++ii) { buf[ARTIST_START + ii] = artist.getBytes()[ii]; } // 写入歌曲名 count = title.getBytes().length; if (count > TITLE_LENGTH) count = TITLE_LENGTH; for (int ii = 0; ii < count; ++ii) { buf[TITLE_START + ii] = title.getBytes()[ii]; } // 写入专辑信息 count = album.getBytes().length; for (int ii = 0; ii < count; ++ii) { buf[ALBUM_START + ii] = album.getBytes()[ii]; } // 写入备注 count = comment.getBytes().length; for (int ii = 0; ii < count; ++ii) { buf[COMMENTS_START + ii] = comment.getBytes()[ii]; } // 写入年代信息 count = year.getBytes().length; for (int ii = 0; ii < count; ++ii) { buf[YEAR_START + ii] = year.getBytes()[ii]; } // 写入轨道信息 buf[TRACK] = (byte) Integer.parseInt(track); // 写入风格 buf[GENRE] = (byte) Integer.parseInt(genre); // 写入音乐文件 try { if (have3v1) { raf.write(buf, 0, LENGTH); } else { raf.seek(raf.length()); raf.write(buf); } raf.close(); } catch (IOException e) { throw new MusicInfoOptException(e.getMessage()); } } // ==============测试程序================= /** * @param args * @throws Exception */ public static void main(String[] args) throws Exception { // TODO Auto-generated method stub File file = new File("c:/01.mp3"); ID3v1Info mp = new ID3v1Info(file); System.out.println(mp.getArtist()); }
}MusicInfo类是一个标准的JavaBean类，提供ID3v1中信息的属性的getter和setter方法
