android - 我正在使用 Exoplayer 2.7.1，我正在尝试播放缓存目录一个 .tmp 格式的文件，但它不播放

Question

在这里我附上了我的代码

`公共类下载音乐活动扩展活动{

/**
 * Estimates bandwidth by listening to data transfers
 */
private static final DefaultBandwidthMeter BANDWIDTH_METER = new DefaultBandwidthMeter();

/**
 * The User-Agent string that should be used.
 */
private static final String USER_AGENT = Constants.EXO_PLAYER;

/**
 * Data source factory
 */
private static final DefaultHttpDataSourceFactory DATA_SOURCE_FACTORY =
        new DefaultHttpDataSourceFactory(USER_AGENT, BANDWIDTH_METER);

/**
 * Notification id
 */
int id = 1;

/**
 * Calculate download percentage
 */
int calculatePercentage = 0;

/**
 * Simple cache file
 */
private SimpleCache cache;

/**
 * Temporary folder
 */
private File tempFolder;

/**
 * Notification Builder
 */
private NotificationCompat.Builder mBuilder;

/**
 * Notification Manager
 */
private NotificationManager mNotifyManager;

/**
 * Starts activity
 *
 * @param context Context of the starting activity
 */
public static void startActivity(Context context) {
    Intent intent = new Intent(context, DownloadMusicActivity.class);
    context.startActivity(intent);
}

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    try {

       //tempFolder=tempFolder.createTempFile(getString(R.string.app_folder_name),".m3u8");
     tempFolder = Util.createTempDirectory(this, getString(R.string.app_folder_name));

    } catch (IOException e) {
        LogMessage.INSTANCE.e(e);
    }

    cache = new SimpleCache(tempFolder, new NoOpCacheEvictor());

    NotificationCompat.BigTextStyle bigTextStyle = new NotificationCompat.BigTextStyle();
    mNotifyManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    mBuilder = new NotificationCompat.Builder(this);
    mBuilder.setContentTitle(getString(R.string.app_name))
            .setColor(getResources().getColor(R.color.signUpButtonGradientStart))
            .setStyle(bigTextStyle)
            .setContentText(getString(R.string.download_progress_notification))
            .setOngoing(true)
            .setAutoCancel(true);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        mBuilder.setSmallIcon(R.drawable.logo);
    } else {
        mBuilder.setSmallIcon(R.mipmap.ic_launcher);
    }

    new DownloadChunksTask().execute();
}

private HlsDownloader getHlsDownloader(String mediaPlaylistUri) {

    return new HlsDownloader(
            Uri.parse(mediaPlaylistUri), new DownloaderConstructorHelper(cache,
            DATA_SOURCE_FACTORY));
}

/**
 * Download the chunk files using AsyncTask
 */
public class DownloadChunksTask extends AsyncTask<Integer, Integer, Integer> {

    //Condition to check the user not subscribed status
    final String audioUrl = "https://contus-skempi-dev.s3.amazonaws.com/encoded/Dancing" +
            ".mp3-playlists.m3u8";

    @Override
    protected Integer doInBackground(Integer... voids) {
        try {
            getHlsDownloader(audioUrl).download(new Downloader.ProgressListener() {
                @Override
                public void onDownloadProgress(Downloader downloader, float
                        downloadPercentage, long
                        downloadedBytes) {

                    calculatePercentage = Math.round(downloadPercentage);

                    // Sets the progress indicator to a max calculatePercentage, the current
                    // completion
                    // percentage and
                    // "determinate" state
                    mBuilder.setProgress(100, Math.round(downloadPercentage), false);
                    // Displays the progress bar for the first time.
                    mNotifyManager.notify(id, mBuilder.build());
                }
            });
        } catch (IOException e) {
            LogMessage.INSTANCE.e(e);
        } catch (InterruptedException e) {
            LogMessage.INSTANCE.e(e);
        }
        return null;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        mNotifyManager.notify(id, mBuilder.build());
    }

    @Override
    protected void onPostExecute(Integer aVoid) {
        super.onPostExecute(aVoid);

        if (calculatePercentage == 100) {
            mBuilder.setContentText(getString(R.string.download_completed));
            // Removes the progress bar
            mBuilder.setProgress(0, 0, false);
            mNotifyManager.notify(id, mBuilder.build());
            Toast.makeText(DownloadMusicActivity.this, getString(R.string.download_completed)
                    , Toast
                    .LENGTH_SHORT).show();
        } else {
            mBuilder.setContentText(getString(R.string.download_progress_failed));
            mBuilder.setProgress(0, 0, false);
            mNotifyManager.notify(id, mBuilder.build());
            Toast.makeText(DownloadMusicActivity.this, getString(R.string.check_internet),
                    Toast
                            .LENGTH_SHORT).show();
            mBuilder.setAutoCancel(true);
        }
    }

    @Override
    protected void onProgressUpdate(Integer... values) {
        // Update progress
        mBuilder.setProgress(100, values[0], false);
        mNotifyManager.notify(id, mBuilder.build());
        super.onProgressUpdate(values);
    }
}

`我使用 HlsDownloader 下载播放列表（.m3u8）文件，并将该文件存储在缓存中，缓存存储每个带有 .tmp 扩展名的文件，我将该缓存文件路径 uri 传递给 exoplayer mediaSource 但它不播放.. .