播放列表存放在裡application中，這個地方可以優化

 @Override
public void onCreate() {
    super.onCreate();
    mPlayer = new MediaPlayer();  //設定播放完成的監聽 mPlayer.setOnCompletionListener(PlayService.this);
    //設定非同步準備的監聽mPlayer.setOnPreparedListener(this);
    mPlayer.setOnBufferingUpdateListener(this);//Register a callback to be invoked when the status of a network stream's buffer has changed.
    // 獲取本地廣播管理器
    lbManager = LocalBroadcastManager.getInstance(getApplicationContext());
    proReceiver = new ProReceiver();
    lbManager.registerReceiver(proReceiver, new IntentFilter(Constants.CAST_ACTION_SEEKBAR_PROCESS));
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    // 判斷是否播放新的歌曲
    if (intent != null) {
        if (intent.getBooleanExtra(Constants.INTENT_EXTRA_CHANGE_MUSIC, false)) {
            // 獲取播放路徑   String path = intent.getStringExtra(Constants.INTENT_EXTRA_MUSIC_PATH);
            curPosition = intent.getIntExtra(Constants.INTENT_EXTRA_MUSIC_POSITION, -1);
            if(curPosition > -1 && curPosition < FMApplication.INSTANCE.getPlayList().size()){
                playMusic(curPosition);
            }
        }else {
            if (mPlayer.isPlaying()) {
                mPlayer.pause();// 暫停
            } else {
                mPlayer.start();// 播放
                new ProgressThread().start();//啟動進度執行緒
            }
        }
    }
    return super.onStartCommand(intent, flags, startId);
}
/**
 * 播放音樂
 * @param position
 */
private void playMusic(int position){
    if(position >= 0 && position < FMApplication.INSTANCE.getPlayList().size()){
        String path = FMApplication.INSTANCE.getPlayList().get(position).getPlayUrl64();
        //播放新歌曲 - reset
        mPlayer.reset();
        try {
            mPlayer.setDataSource(path);
            mPlayer.prepareAsync();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
/**
 * 播放一首音樂結束的回撥方法，傳送播放完畢的廣播
 * @param mediaPlayer
 */
@Override
public void onCompletion(MediaPlayer mediaPlayer) {
    if(++curPosition == FMApplication.INSTANCE.getPlayList().size())
        curPosition = 0;
    playMusic(curPosition);

    // TODO 傳送播放完畢的廣播
    Intent intent = new Intent(Constants.CAST_ACTION_MUSIC_COMPLETE);
    intent.putExtra(Constants.INTENT_EXTRA_MUSIC_POSITION, curPosition);
    lbManager.sendBroadcast(intent);
}
/**
 * 快取資料成功回撥
 * @param mediaPlayer
 */
@Override
public void onPrepared(MediaPlayer mediaPlayer) {
    if (mPlayer.isPlaying()) {
        mPlayer.pause();// 暫停
    } else {
        mPlayer.start();// 播放
        new ProgressThread().start();//啟動進度執行緒
        // TODO 傳送開始播放廣播給 PlayActivity
        Intent intent = new Intent(Constants.CAST_ACTION_MUSIC_START);
        lbManager.sendBroadcast(intent);
    }
}
/**
 * 快取
 * @param mediaPlayer
 * @param progress
 */
@Override
public void onBufferingUpdate(MediaPlayer mediaPlayer, int progress) {
    // TODO 傳送開始播放廣播給 PlayActivity
    Intent intent = new Intent(Constants.CAST_ACTION_BUFFERING_UPDATE);
    sumLen = mPlayer.getDuration();
    if(progress != 100){
        progress = (int) (progress / 100f  *  sumLen);
        intent.putExtra(Constants.INTENT_EXTRA_BUFFERING_UPDATE, progress);
        intent.putExtra(Constants.INTEXT_EXTRA_MUSIC_TOTAL_LEN, sumLen);總時長
        lbManager.sendBroadcast(intent);
    }
}
/**
 * 計算播放進度的執行緒
 */
class ProgressThread extends Thread {
    @Override
    public void run() {
        try {
            while (mPlayer != null && mPlayer.isPlaying()) {
                sumLen = mPlayer.getDuration();
                int currentPosition = mPlayer.getCurrentPosition();
                // 準備傳送進度廣播
                Intent intent = new Intent(Constants.CAST_ACTION_MUSIC_PROGRESS);
                intent.putExtra(Constants.INTEXT_EXTRA_MUSIC_TOTAL_LEN, sumLen);
                intent.putExtra(Constants.INTENT_EXTRA_MUSIC_CUR_LEN, currentPosition);
                lbManager.sendBroadcast(intent);

                Thread.sleep(500);//200ms發一次 ，必須大於0，否則 ANR
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
/**
 * 進度廣播接收者
 */
class ProReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        int cur = intent.getIntExtra(Constants.INTENT_EXTRA_MUSIC_CUR_LEN, 0);//從播放介面傳送過來的進度

        mPlayer.seekTo(cur);
    }
}
@Override
public void onDestroy() {
    super.onDestroy();
    lbManager.unregisterReceiver(proReceiver);
    mPlayer.release();
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
    return null;
}