我在Android布局文件中添加了进度条、上下曲暂停播放按钮、时间、listview组件，请帮我补全java代码

好的，以下是可能的代码实现：

public class MainActivity extends AppCompatActivity {
    
    private ProgressBar progressBar;
    private ImageButton playBtn, pauseBtn, prevBtn, nextBtn;
    private TextView timeTextView;
    private ListView listView;
    private MediaPlayer mediaPlayer;
    private ArrayList<String> songsList = new ArrayList<String>();
    private ArrayAdapter<String> adapter;
    private int currentSongIndex = 0;
    private Handler mHandler = new Handler();
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        // 初始化各个组件
        progressBar = findViewById(R.id.progress_bar);
        playBtn = findViewById(R.id.play_button);
        pauseBtn = findViewById(R.id.pause_button);
        prevBtn = findViewById(R.id.prev_button);
        nextBtn = findViewById(R.id.next_button);
        timeTextView = findViewById(R.id.time_text_view);
        listView = findViewById(R.id.list_view);
        mediaPlayer = new MediaPlayer();
        
        // 添加音乐
        songsList.add("song1.mp3");
        songsList.add("song2.mp3");
        // ...
        
        // 初始化listView的adapter
        adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, songsList);
        listView.setAdapter(adapter);
        
        // 设置监听器
        playBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                playSong(currentSongIndex);
            }
        });
        
        pauseBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                pauseSong();
            }
        });
        
        prevBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                playPrevSong();
            }
        });
        
        nextBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                playNextSong();
            }
        });
        
        // 设置mediaPlayer的监听器
        mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mediaPlayer) {
                // 播放完毕后自动播放下一首
                playNextSong();
            }
        });
    }
    
    // 播放指定位置的歌曲
    private void playSong(int songIndex) {
        try {
            mediaPlayer.reset();
            mediaPlayer.setDataSource(songsList.get(songIndex));
            mediaPlayer.prepare();
            mediaPlayer.start();
            
            // 更新进度条和时间
            updateProgressBar();
            updateSongTime();
            
            // 更新播放/暂停按钮的图标
            playBtn.setVisibility(View.GONE);
            pauseBtn.setVisibility(View.VISIBLE);
            
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    // 暂停当前歌曲
    private void pauseSong() {
        mediaPlayer.pause();
        
        // 更新播放/暂停按钮的图标
        playBtn.setVisibility(View.VISIBLE);
        pauseBtn.setVisibility(View.GONE);
    }
    
    // 播放上一首歌曲
    private void playPrevSong() {
        currentSongIndex--;
        if (currentSongIndex < 0) {
            currentSongIndex = songsList.size() - 1;
        }
        playSong(currentSongIndex);
    }
    
    // 播放下一首歌曲
    private void playNextSong() {
        currentSongIndex++;
        if (currentSongIndex >= songsList.size()) {
            currentSongIndex = 0;
        }
        playSong(currentSongIndex);
    }
    
    // 更新进度条和时间
    private void updateProgressBar() {
        mHandler.postDelayed(mUpdateTimeTask, 100);
    }
    
    private Runnable mUpdateTimeTask = new Runnable() {
        public void run() {
            long totalDuration = mediaPlayer.getDuration();
            long currentDuration = mediaPlayer.getCurrentPosition();
 
            // 更新进度条
            int progress = (int)(getProgressPercentage(currentDuration, totalDuration));
            progressBar.setProgress(progress);
 
            // 更新时间
            timeTextView.setText(milliSecondsToTimer(currentDuration) + "/" + milliSecondsToTimer(totalDuration));
 
            // Running this thread after 100 milliseconds
            mHandler.postDelayed(this, 100);
        }
    };
    
    // 根据当前时间和总时间计算进度条的百分比
    private int getProgressPercentage(long currentDuration, long totalDuration){
        Double percentage = (double) 0;
 
        long currentSeconds = (int) (currentDuration / 1000);
        long totalSeconds = (int) (totalDuration / 1000);
 
        // calculating percentage
        percentage =(((double)currentSeconds)/totalSeconds)*100;
 
        // return percentage
        return percentage.intValue();
    }
    
    // 将毫秒转换为“00:00”格式的时间
    private String milliSecondsToTimer(long milliseconds){
        String finalTimerString = "";
        String secondsString = "";
 
        // Convert total duration into time
           int hours = (int)( milliseconds / (1000*60*60));
           int minutes = (int)(milliseconds % (1000*60*60)) / (1000*60);
           int seconds = (int) ((milliseconds % (1000*60*60)) % (1000*60) / 1000);
           // Add hours if there
           if(hours > 0){
               finalTimerString = hours + ":";
           }
 
           // Prepending 0 to seconds if it is one digit
           if(seconds < 10){
               secondsString = "0" + seconds;
           }else{
               secondsString = "" + seconds;}
 
           finalTimerString = finalTimerString + minutes + ":" + secondsString;
 
        // return timer string
        return finalTimerString;
    }
    
}

注意，上面的代码仅供参考，可能需要根据具体的需求做出修改。例如，添加音乐文件时需要将文件放在正确的位置，并且需要添加相应的权限；listView的adapter可以使用自定义的adapter等。