一个更完整和功能更强大的音乐播放器的代码

以下是一个更完整和功能更强大的 Java 音乐播放器的代码示例，它包含了播放、暂停、停止、快进/快退、播放列表等功能：

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.swing.DefaultListModel;
import javax.swing.JList;
import javax.swing.ListSelectionModel;

public class MusicPlayer {
    
    private Clip clip;
    private boolean playing = false;
    private boolean paused = false;
    private int currentFrame = 0;
    private int frameRate = 0;
    private List<String> playlist;
    private DefaultListModel<String> playlistModel;
    
    public MusicPlayer() {
        playlist = new ArrayList<String>();
        playlistModel = new DefaultListModel<String>();
    }
    
    public void play(String filePath) {
        try {
            if (clip != null && clip.isActive()) {
                clip.stop();
            }
            clip = AudioSystem.getClip();
            clip.open(AudioSystem.getAudioInputStream(new File(filePath)));
            clip.start();
            playing = true;
            paused = false;
            currentFrame = clip.getFramePosition();
            frameRate = (int)clip.getFormat().getFrameRate();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    public void pause() {
        if (clip != null && clip.isActive()) {
            clip.stop();
            paused = true;
            playing = false;
            currentFrame = clip.getFramePosition();
        }
    }
    
    public void resume() {
        if (clip != null && paused) {
            clip.setFramePosition(currentFrame);
            clip.start();
            playing = true;
            paused = false;
        }
    }
    
    public void stop() {
        if (clip != null && clip.isActive()) {
            clip.stop();
            playing = false;
            paused = false;
            currentFrame = 0;
        }
    }
    
    public void skip(int seconds) {
        if (clip != null && clip.isActive()) {
            currentFrame += seconds * frameRate;
            clip.setFramePosition(currentFrame);
        }
    }
    
    public void addToPlaylist(String filePath) {
        if (!playlist.contains(filePath)) {
            playlist.add(filePath);
            playlistModel.addElement(filePath);
        }
    }
    
    public void removeFromPlaylist(int index) {
        if (index >= 0 && index < playlist.size()) {
            playlist.remove(index);
            playlistModel.remove(index);
        }
    }
    
    public void clearPlaylist() {
        playlist.clear();
        playlistModel.clear();
    }
    
    public void playFromPlaylist(int index) {
        if (index >= 0 && index < playlist.size()) {
            play(playlist.get(index));
        }
    }
    
    public JList<String> getPlaylist() {
        JList<String> list = new JList<String>(playlistModel);
        list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        return list;
    }
    
    public boolean isPlaying() {
        return playing;
    }
    
    public boolean isPaused() {
        return paused;
    }
    
    public static void main(String[] args) {
        MusicPlayer player = new MusicPlayer();
        player.addToPlaylist("path/to/music1.mp3");
        player.addToPlaylist("path/to/music2.mp3");
        player.addToPlaylist("path/to/music3.mp3");
        player.playFromPlaylist(0);
    }
}

在上述代码中，我们添加了一个 `playing` 和 `paused` 的状态变量，用于跟踪当前音乐的播放状态。我们还添加了 `currentFrame` 和 `frameRate` 变量，用于实现快进/快退的功能。`addToPlaylist()`、`removeFromPlaylist()`、`clearPlaylist()` 和 `playFromPlaylist()` 方法用于管理播放列表。

我们还添加了一个 `getPlaylist()` 方法，用于返回一个包含播放列表的 `JList` 对象，以便在 GUI 界面上显示播放列表。

请注意，如果你需要在 GUI 界面上实现播放器，你需要在这个基础上进行更多的修改和扩展。