Download a file programmatically on Android

I am downloading files from web server programmatically. After download is completed, I checked the file. The size ,extension and all other parameters are correct but when I try to play that file in media player it is showing that it is corrupted.

Here is my code:

    byte[] b = null;
    InputStream in = null;
    b = new byte[Integer.parseInt(size)];    // size of the file.
    in = OpenHttpConnection(URL);            
    in.read(b);
    in.close();

    File folder = new File("/sdcard", "folder");
   boolean check = folder.mkdirs();

   Log.d("HttpDownload", "check " + check);

   File myFile = new File("/sdcard/folder/" + name);


    myFile.createNewFile();
   OutputStream filoutputStream = new FileOutputStream(myFile);

   filoutputStream.write(b);

   filoutputStream开发者_运维百科.flush();

   filoutputStream.close();

This is some working code I have for downloading a given URL to a given File object. The File object (outputFile) has just been created using new File(path), I haven't called createNewFile or anything.

private static void downloadFile(String url, File outputFile) {
  try {
      URL u = new URL(url);
      URLConnection conn = u.openConnection();
      int contentLength = conn.getContentLength();

      DataInputStream stream = new DataInputStream(u.openStream());

        byte[] buffer = new byte[contentLength];
        stream.readFully(buffer);
        stream.close();

        DataOutputStream fos = new DataOutputStream(new FileOutputStream(outputFile));
        fos.write(buffer);
        fos.flush();
        fos.close();
  } catch(FileNotFoundException e) {
      return; // swallow a 404
  } catch (IOException e) {
      return; // swallow a 404
  }
}

Permission

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_INTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_INTERNAL_STORAGE" />
<uses-permission android:name="android.permission.DOWNLOAD_WITHOUT_NOTIFICATION" />

Download Fuction Code

 public void downloadFile() {
        String DownloadUrl = audio1;
        DownloadManager.Request request1 = new DownloadManager.Request(Uri.parse(DownloadUrl));
        request1.setDescription("Sample Music File");   //appears the same in Notification bar while downloading
        request1.setTitle("File1.mp3");
        request1.setVisibleInDownloadsUi(false);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            request1.allowScanningByMediaScanner();
            request1.setNotificationVisibility(DownloadManager.Request.VISIBILITY_HIDDEN);
        }
        request1.setDestinationInExternalFilesDir(getApplicationContext(), "/File", "Question1.mp3");

        DownloadManager manager1 = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
        Objects.requireNonNull(manager1).enqueue(request1);
        if (DownloadManager.STATUS_SUCCESSFUL == 8) {
        DownloadSuccess(); 
        }
    }

private void down(String string)
    {

        try
        {
            URL url = new URL(URL);
            HttpURLConnection c = (HttpURLConnection) url.openConnection();
            c.setRequestMethod("GET");
            c.setDoOutput(true);
            c.connect();

            String PATH = Environment.getExternalStorageDirectory().toString()
                    + "/load";
            Log.v("LOG_TAG", "PATH: " + PATH);

            File file = new File(PATH);
            file.mkdirs();
            File outputFile = new File(file, option14[i].toString());
            FileOutputStream fos = new FileOutputStream(outputFile);
            InputStream is = c.getInputStream();

            byte[] buffer = new byte[4096];
            int len1 = 0;

            while ((len1 = is.read(buffer)) != -1)
            {
                fos.write(buffer, 0, len1);
            }

            fos.close();
            is.close();

            Toast.makeText(this, " A new file is downloaded successfully",
                    Toast.LENGTH_LONG).show();

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

    }

I checked this stackoverflow question but it looks like there is not a download Intent.

Did you try setting the WRITE_EXTERNAL_STORAGE in the android manifest?

read on an input stream doesn't guarntee that the entire contents of the file will be pulled down in one go. Check the return value on that in.read(b); line. It might look something like this:

if(in.read(b) != size)
    Log.e("Network","Failed to read all data!");

That'll tell you, at the very least, if you're getting all your data from the networking layer. If you only got a partial read, but you're still writing the full byte array to disk, that might explain why the media player thinks the file is corrupt.