前几天写了一个NB的音乐插件，自己用了一下，还是挺方便的，后来想想，如果能把歌词也显示出来那就更好了。呵呵，怎么办呢，只有自己写了，在显示歌词之前，必须要知道目前正在播放的MP3是什么内容啊，一点可以从文件名得到一些信息，还有一点就是从MP3文件里面得到这个MP3的信息，我这里实现的ID3V1的格式标签，APEV2也想实现，无奈找不到相关的资料，不知道APEV2的数据结构是怎么样的，所以也无从分析。目前已经写完了 ID3V1格式标签的读取和写入。并且NB的音乐插件也实现了本地歌词的搜索，先把ID3V1的文件结构的类文件帖一下，大家一起分享。
MP3的ID3V1的信息结构是很有规律的，它一般是出现在MP3文件的最后128个字节上，并且是以“TAG”开头。我这里把它封装成一个类了。
截图如下：






代码如下：
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package com.hadeslee.music;

/**
* 一个歌曲信息的类的结构表示
* 这个歌曲是使用ID3V1的信息存储结构的
* @author hadeslee
*/
public class SongInfo {

private final String TAG = "TAG"; //文件头1-3
private String songName; //歌曲名4-33
private String artist; //歌手名34-63
private String album; //专辑名61-93
private String year; //年94-97
private String comment; //备注98-125
private byte r1, r2, r3; //三个保留位126，127，128
private boolean valid; //是否合法
public transient String fileName; //此歌曲对应的文件名,没有封装
public SongInfo(byte[] data) {
if (data.length != 128) {
throw new RuntimeException("数据长度不合法:" + data.length);
}
String tag = new String(data, 0, 3);
//只有前三个字节是TAG才处理后面的字节
if (tag.equalsIgnoreCase("TAG")) {
valid = true;
songName = new String(data, 3, 30).trim();
artist = new String(data, 33, 30).trim();
album = new String(data, 63, 30).trim();
year = new String(data, 93, 4).trim();
comment = new String(data, 97, 28).trim();
r1 = data[125];
r2 = data[126];
r3 = data[127];
} else {
valid = false;
}
}

public SongInfo() {
}

/**
* 返回是否合法
* @return 是否
*/
public boolean isValid() {
return valid;
}

/**
* 得到此对象的128个字节的表示形式
* @return
*/
public byte[] getBytes() {
byte[] data = new byte[128];
System.arraycopy(TAG.getBytes(), 0, data, 0, 3);
byte[] temp = songName.getBytes();
System.arraycopy(temp, 0, data, 3, temp.length > 30 ? 30 : temp.length);
temp = artist.getBytes();
System.arraycopy(temp, 0, data, 33, temp.length > 30 ? 30 : temp.length);
temp = album.getBytes();
System.arraycopy(temp, 0, data, 63, temp.length > 30 ? 30 : temp.length);
temp = year.getBytes();
System.arraycopy(temp, 0, data, 93, temp.length > 4 ? 4 : temp.length);
temp = comment.getBytes();
System.arraycopy(temp, 0, data, 97, temp.length > 28 ? 28 : temp.length);
data[125] = r1;
data[126] = r2;
data[127] = r3;
return data;
}

public String getArtist() {
return artist;
}

public void setArtist(String authorName) {
this.artist = authorName;
}

public String getComment() {
return comment;
}

public void setComment(String comment) {
this.comment = comment;
}

public byte getR1() {
return r1;
}

public void setR1(byte r1) {
this.r1 = r1;
}

public byte getR2() {
return r2;
}

public void setR2(byte r2) {
this.r2 = r2;
}

public byte getR3() {
return r3;
}

public void setR3(byte r3) {
this.r3 = r3;
}

public String getSongName() {
return songName;
}

public void setSongName(String songName) {
if(songName==null){
throw new NullPointerException("歌名不能是null!");
}
valid=true;
this.songName = songName;
}

public String getAlbum() {
return album;
}

public void setAlbum(String specialName) {
this.album = specialName;
}

public String getYear() {
return year;
}

public void setYear(String year) {
this.year = year;
}

}

编辑对话框的代码：
/*
* SongInfoDialog.java
*
* Created on 2007年11月26日, 下午4:12
*/
package com.hadeslee.music;

import java.awt.Dialog;
import java.awt.Frame;
import java.io.File;
import java.io.RandomAccessFile;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
*
* @author hadeslee
*/
public class SongInfoDialog extends javax.swing.JDialog {

private SongInfo info; //歌曲信息对象
private File file; //文件对象
private boolean valid; //表示原来这个文件是不是合法的,如果不是,就要重新写入128个字节
/** Creates new form SongInfoDialog */
public SongInfoDialog(java.awt.Frame parent, boolean modal) {
super(parent, modal);
initComponents();
}

public SongInfoDialog(Dialog parent, boolean modal) {
super(parent, modal);
initComponents();
}

public SongInfoDialog(Frame parent, boolean modal, File file) {
this(parent, modal);
this.file = file;
init();
}

public SongInfoDialog(Dialog parent, boolean modal, File file) {
this(parent, modal);
this.file = file;
init();
}

/**
* 初始化
*/
private void init() {
try {
fileName.setText(file.toString());
RandomAccessFile ra = new RandomAccessFile(file, "r");
byte[] buffer = new byte[128];
ra.seek(ra.length() - 128);
ra.read(buffer);
info = new SongInfo(buffer);
valid = info.isValid();
title.setText(info.getSongName());
artist.setText(info.getArtist());
album.setText(info.getAlbum());
year.setText(info.getYear());
comment.setText(info.getComment());
r2.setText("" + info.getR2());
r3.setText("" + info.getR3());
ra.close();
} catch (Exception ex) {
Logger.getLogger(SongInfoDialog.class.getName()).log(Level.SEVERE, null, ex);
}
}

/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
//
private void initComponents() {

jLabel5 = new javax.swing.JLabel();
fileName = new javax.swing.JTextField();
jPanel1 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
title = new javax.swing.JTextField();
jLabel2 = new javax.swing.JLabel();
artist = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
jLabel4 = new javax.swing.JLabel();
album = new javax.swing.JTextField();
jLabel6 = new javax.swing.JLabel();
r2 = new javax.swing.JTextField();
year = new javax.swing.JTextField();
jLabel7 = new javax.swing.JLabel();
r3 = new javax.swing.JTextField();
jLabel8 = new javax.swing.JLabel();
jScrollPane1 = new javax.swing.JScrollPane();
comment = new javax.swing.JTextArea();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
jLabel9 = new javax.swing.JLabel();

setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);

jLabel5.setText("文件名:");

fileName.setEditable(false);

jPanel1.setBorder(javax.swing.BorderFactory.createTitledBorder("标签"));

jLabel1.setText("标 题:");

jLabel2.setText("艺术家:");

jLabel3.setText("专 辑:");

jLabel4.setText("年份:");

jLabel6.setText("音轨:");

r2.setEditable(false);

jLabel7.setText("流 派:");

r3.setEditable(false);

jLabel8.setText("备 注:");

comment.setColumns(20);
comment.setRows(5);
jScrollPane1.setViewportView(comment);

javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(title, javax.swing.GroupLayout.PREFERRED_SIZE, 183, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(artist, javax.swing.GroupLayout.DEFAULT_SIZE, 185, Short.MAX_VALUE)
.addContainerGap())
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(album, javax.swing.GroupLayout.DEFAULT_SIZE, 110, Short.MAX_VALUE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel7)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(r3, javax.swing.GroupLayout.DEFAULT_SIZE, 110, Short.MAX_VALUE)))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel4)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(year, javax.swing.GroupLayout.PREFERRED_SIZE, 31, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel6)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(r2, javax.swing.GroupLayout.PREFERRED_SIZE, 30, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap())
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel8)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 185, Short.MAX_VALUE)
.addContainerGap())))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel1)
.addComponent(title, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(artist, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(r2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel6)
.addComponent(album, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel4)
.addComponent(year, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel7)
.addComponent(r3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel8)
.addContainerGap(42, Short.MAX_VALUE))
.addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 57, Short.MAX_VALUE)))
);

jButton1.setText("重新读取文件");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});

jButton2.setText("保存到文件");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});

jButton3.setText("取消");
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});

jLabel9.setForeground(new java.awt.Color(255, 0, 102));
jLabel9.setText("注:目前只支持ID3v1格式标签的存取");

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jLabel5)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(fileName, javax.swing.GroupLayout.DEFAULT_SIZE, 221, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addComponent(jButton1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jButton3))
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jLabel9))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel5)
.addComponent(fileName, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1)
.addComponent(jButton2)
.addComponent(jButton3))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jLabel9)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);

pack();
}//
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
this.dispose();
}

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
doSave();
}

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
init();
}

private void doSave() {
try {
info.setAlbum(album.getText());
info.setArtist(artist.getText());
info.setComment(comment.getText());
info.setR1((byte) 0);
try {
info.setR2(Byte.parseByte(r2.getText()));
info.setR3(Byte.parseByte(r3.getText()));
} catch (Exception exe) {
exe.printStackTrace();
}
info.setYear(year.getText());
info.setSongName(title.getText());
RandomAccessFile raf = new RandomAccessFile(file, "rw");
//如果这个文件原来就是合法的,那么就不用新起128个字节了
if (valid) {
raf.seek(raf.length() - 128);
} else {//否则就在末层加上128个字节
raf.seek(raf.length());
}
raf.write(info.getBytes());
raf.close();
this.dispose();
} catch (Exception ex) {
Logger.getLogger(SongInfoDialog.class.getName()).log(Level.SEVERE, null, ex);
}
}

/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {

public void run() {
SongInfoDialog dialog = new SongInfoDialog(new javax.swing.JFrame(), true);
dialog.addWindowListener(new java.awt.event.WindowAdapter() {

public void windowClosing(java.awt.event.WindowEvent e) {
System.exit(0);
}
});
dialog.setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JTextField album;
private javax.swing.JTextField artist;
private javax.swing.JTextArea comment;
private javax.swing.JTextField fileName;
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JLabel jLabel7;
private javax.swing.JLabel jLabel8;
private javax.swing.JLabel jLabel9;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextField r2;
private javax.swing.JTextField r3;
private javax.swing.JTextField title;
private javax.swing.JTextField year;
// End of variables declaration
}


有歌词的插件，由于还不是很完善，所以过一两天再发布，呵呵。：）