53     private MediaPlayer mMediaPlayer;  field in MainActivity
154         if (mMediaPlayer == null) {  in playMusic()
155             mMediaPlayer = MediaPlayer.create(this, R.raw.sound);  in playMusic()
156             mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {  in playMusic()
165         mMediaPlayer.start();  in playMusic()
172         if (mMediaPlayer != null) {  in stopMusic()
173             mMediaPlayer.stop();  in stopMusic()
174             mMediaPlayer.release();  in stopMusic()
175             mMediaPlayer = null;  in stopMusic()
257         if (mMediaPlayer != null) {  in onStop()
258             mMediaPlayer.release();  in onStop()
259             mMediaPlayer = null;  in onStop()