在MediaPlayer的生命周期中，应该在合适的时机调用prepare()方法。示例代码如下：

private MediaPlayer mediaPlayer;

private void initializeMediaPlayer() {
    mediaPlayer = new MediaPlayer();
    mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
    try {
        mediaPlayer.setDataSource("your song url goes here");
        mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
            @Override
            public void onPrepared(MediaPlayer mp) {
                mediaPlayer.start();
            }
        });
        mediaPlayer.prepare();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

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