android 播放本地音乐

 private void startMusic() {
       String pathMusic=APP.downfile+"a.mp3";
        try {

                mediaPlayer = new MediaPlayer();

                mediaPlayer.setDataSource(pathMusic);
                mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
                //mediaPlayer.prepare();//同步的准备方法。
                mediaPlayer.prepareAsync();//异步的准备
                mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mp) {
                        mediaPlayer.start();
                        start.setEnabled(false);
                    }
                });
                mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                    @Override
                    public void onCompletion(MediaPlayer mp) {
                        start.setEnabled(true);
                    }
                });

        } catch (Exception e) {
            e.printStackTrace();
           
        }
    }