MainActivity.java MusicPlayer PAB

package www.ariwibawa.my.id.musicplayer;

import android.content.res.AssetFileDescriptor;
import android.media.MediaMetadataRetriever;
import android.net.Uri;
import android.os.Bundle;
import android.media.MediaPlayer;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.SeekBar;
import android.widget.TextView;
import android.os.Handler;
import java.util.concurrent.TimeUnit;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {
    private MediaPlayer mediaPlayer;
    private TextView songName, songDuration;
    private SeekBar seekBar;
    private double timeStart = 0, finalTime = 0;
    private int forwardTime = 20000, backwardTime = 20000;
    private Handler durationHandler = new Handler();
    private boolean swtch = false;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        songName = (TextView) findViewById(R.id.songName);
        songDuration = (TextView) findViewById(R.id.songDuration);
        mediaPlayer = MediaPlayer.create(this, R.raw.music);

        MediaMetadataRetriever meta = new MediaMetadataRetriever();

        final AssetFileDescriptor afd=getResources().openRawResourceFd(R.raw.music);
        meta.setDataSource(afd.getFileDescriptor(),afd.getStartOffset(),afd.getLength());

        String music_duration = meta.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION);
        finalTime = Long.parseLong(music_duration);

        Log.v("musicDuration", "Duration : "+music_duration);

        seekBar = (SeekBar) findViewById(R.id.seekBar);
        songName.setText("Nokia Ring Tone.mp3");
        seekBar.setMax((int) finalTime);
        seekBar.setOnSeekBarChangeListener(new yourListener() );
        seekBar.setClickable(false);
    }

    private class yourListener implements SeekBar.OnSeekBarChangeListener {
        public void onProgressChanged(SeekBar seekBar, int progress,
                                      boolean fromUser){
            if(swtch){
                mediaPlayer.seekTo(progress);
            }
        }

        public void onStartTrackingTouch(SeekBar seekBar){
            swtch = true;
        }

        public void onStopTrackingTouch(SeekBar seekBar){
            swtch = false;
        }
    }

    private Runnable updateSeekBarTime = new Runnable() {
        @Override
        public void run() {
            timeStart = mediaPlayer.getCurrentPosition();
            seekBar.setProgress((int) timeStart);
            double timeRemaining = finalTime - timeStart;
            songDuration.setText(String.format("%d min, %d sec",
                    TimeUnit.MILLISECONDS.toMinutes((long) timeRemaining),
                    TimeUnit.MILLISECONDS.toSeconds((long) timeRemaining) -
                    TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes((long) timeRemaining))));
            durationHandler.postDelayed(this, 1000);
        }
    };
    public void play(View view){
        mediaPlayer.start();
        timeStart = mediaPlayer.getCurrentPosition();
        seekBar.setProgress((int) timeStart);
        durationHandler.postDelayed(updateSeekBarTime, 100);
    }
    public void pause(View view){
        mediaPlayer.pause();
    }
    public void forward(View view){
        timeStart = timeStart + forwardTime;
        mediaPlayer.seekTo((int) timeStart);
    }
    public void backforward(View view){
        timeStart = timeStart + backwardTime;
        mediaPlayer.seekTo((int) timeStart);
    }
}