private MediaPlayer mediaPlayer;

if(uri!=null) {
    
    Uri   uri1 = Uri.parse(uri);
    try {
        mediaPlayer = new MediaPlayer();
        mediaPlayer.setDataSource(this, uri1);
        mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
        mediaPlayer.prepareAsync();
        mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {

            @Override
            public void onPrepared(MediaPlayer mp) {
                Log.e("MediaPlayer ","開始播放");
                mp.start();
            }
        });
    } catch (Exception e) {
        e.printStackTrace();
    }
}

@Override
protected void onDestroy() {
    super.onDestroy();
 
    if (mediaPlayer != null && mediaPlayer.isPlaying()) {
        mediaPlayer.stop();
        mediaPlayer.release();
        mediaPlayer = null;
    }

}

// 設定迴圈播放
               //   mediaPlayer.setLooping(true);
                mediaPlayer.setOnCompletionListener(new OnCompletionListener() {
                    @Override
                    public void onCompletion(MediaPlayer mp) {
                        // 在播放完畢被回撥
                        play();                        
                    }
                });