DownloadManager与InputStream.read（）

Question

I have 2 simple implementation of DownloadManager and custom download task:

• DownloadManager

   public void onCreate(Bundle savedInstanceState) { ... mDownloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE); } private void startDownload(String link) Uri uri=Uri.parse(link); DownloadManager.Request req = new DownloadManager.Request(uri); req.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE) .setAllowedOverRoaming(false) .setVisibleInDownloadsUi(false) .setTitle(getString(R.string.app_name)) .setDescription(getString(R.string.waiting_for_downloading)) .setDestinationInExternalPublicDir(dataPath,fileName); lastDownload = mDownloadManager.enqueue(req); } private void queryStatus() { Cursor c = mDownloadManager.query(new DownloadManager.Query().setFilterById(lastDownload)); if (c == null) return; switch (c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS))) { case DownloadManager.STATUS_FAILED: downloadError(); break; case DownloadManager.STATUS_RUNNING: ... break; case DownloadManager.STATUS_SUCCESSFUL: ... break; default: break; } c.close(); } 

• custom download task

   new AsyncTask<String, Void, Void>() { @Override protected Void doInBackground(String... params) { try { URL url = new URL(params[0]); InputStream input = new BufferedInputStream(url.openStream()); OutputStream output = new FileOutputStream(saveFile); byte data[] = new byte[1024]; while ((count = input.read(data)) != -1) { output.write(data, 0, count); } output.flush(); output.close(); input.close(); } catch (Exception e) { downloadError(); } return null; } } 

in general cases both methods works ok, but on some devices (for ex xiaomi android 6) DownloadManager works 2-3 times slower or i got DownloadManager.STATUS_FAILED error. but why? is DownloadManager unstable? or it's smth about settings?

ps: i would like to use DownloadManager because of customization that i shouldn't implement by myself like set up allowed network or show progress in notification area.

update v0.1

1) I have handler that called queryStatus() check one time per 1 sec.

2) trying to connect to another wi-fi network with nexus phone - DownloadManager works ok, but custom implementation fails...

update v0.2

tried to call AsyncTask downloader from Service (to continue download in case user close the app without canceling process) , UI updates via BroadcastReceiver + sendBreadcase() call from the Service - result: downloading became several times slower and now (from time to time) I got an unexpected end of stream exception. [Trying the same files I've downloaded when makes call from Activity ]

update v0.3

forgot to notice: DownloadManager fails with 1008 reason = ERROR_CANNOT_RESUME

tried ION also. looks if works better than DownloadManager but some times got an error End of data reached before content length was read: 70385664/77217546

so, still looking the most stable solution...

Answer 1

ok... there was a lot of tests passed with different wi-fi connections and set of devices. ION grant the most stable results.