media player android studio

import android.app.Activity;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.SeekBar;
import android.widget.TextView;

public class MainActivity extends Activity {

    private MediaPlayer mMedia;
    private Handler handler = new Handler();
    private SeekBar seekBar;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if(mMedia != null){
            mMedia.release();
        }

        final TextView txtView = (TextView)findViewById(R.id.textView1);
        txtView.setText("Source : music.mp3");

        /* Resource in R.
         * mMedia = MediaPlayer.create(this, R.raw.music);
         * mMedia.start();
         */

        /*
         * from DataSource
         * mMedia = new MediaPlayer();
         * mMedia.setDataSource("http://www.thaicreate.com/music/mymusic.mp3");
         * mMedia.start();
         *
         */
        mMedia = MediaPlayer.create(this, R.raw.music);

        seekBar = (SeekBar)findViewById(R.id.seekBar1);
        seekBar.setMax(mMedia.getDuration());
        seekBar.setOnTouchListener(new OnTouchListener() {
            public boolean onTouch(View v, MotionEvent event) {
                UpdateseekChange(v);

                return false;
            }
        });


        final Button btn1 = (Button) findViewById(R.id.button1); // Start



        // Start
        btn1.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {

                if (mMedia.isPlaying()) {
                txtView.setText("Playing : music.mp3....");
                    mMedia.pause();
                } else {
                    txtView.setText("pause : music.mp3....");
                    mMedia.start();
                }
            }
        });


    }

    private void UpdateseekChange(View v){
        if(mMedia.isPlaying()){
            SeekBar sb = (SeekBar)v;
            mMedia.seekTo(sb.getProgress());
        }
    }

    public void startPlayProgressUpdater() {
        seekBar.setProgress(mMedia.getCurrentPosition());

        if (mMedia.isPlaying()) {
            Runnable notification = new Runnable() {
                public void run() {
                    startPlayProgressUpdater();
                }
            };
            handler.postDelayed(notification,1000);
        }
    }

    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        if(mMedia != null && fromUser){
            mMedia.seekTo(progress * 1000);
        }
    }

    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        if(mMedia != null){
            mMedia.release();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

}