Retrieve file path from caught DownloadManager intent

Question

Since Android 4.2 if a user downloads some file in the browser the DownloadManager is used. If the user clicks the 'download complete' notification an Intent is and was always launched. Before Android 4.2 the intent used to have the downloaded file's path in the content, such that:

intent.getData()

would return a String such as file:///storage/emulated/0/Download/some_file.ext. However, since Android 4.2 the download manager broadcasts and intent with a content scheme, such as content://downloads/all_downloads/2334.

How do I retrieve the local file path for a downloaded file?

I've tried the following:

public static String getRealPathFromURI(Uri contentUri, Activity activity) {
    DownloadManager downloadManager = (DownloadManager) activity.getSystemService(Activity.DOWNLOAD_SERVICE);
    String[] contentParts = contentUri.getEncodedPath().split("/");
    Cursor q = downloadManager.query(new DownloadManager.Query().setFilterById(Integer.parseInt(contentParts[contentParts.length - 1])));
    if (q == null) {
        // Download no longer exists
        return null;
    }
    q.moveToFirst();
    return q.getString(q.getColumnIndex(DownloadManager.COLUMN_LOCAL_FILENAME));
}

But the cursor never returns any rows (so q.getCount() == 0 and therefor the last return statement throws an exception). Also, the hack by parsing the download file id from the Uri seems odd.

UPDATE: I have also tried:

input = getActivity().getContentResolver().openInputStream(contentUri);

but this returns an error stating

Permission Denial: reading com.android.providers.downloads.DownloadProvider uri content://downloads/all_downloads/2334 from pid=30950, uid=10064 requires android.permission.ACCESS_ALL_DOWNLOADS, or grantUriPermission()

Clearly I can't access the downloads (as my app did not initiate them - the browser did) through the ContentProvider.

Answer 1

Here's what worked. First, you can't (and shouldn't want to) get the file path as botteaap correctly pointed out. (Credits to him for setting me on the right path.) Instead you get a temporary permission automatically to access the file content, using:

InputStream input = getContentResolver().openInputStream(intent.getData());

You can read this InputStream like any other in Java. It seems there is no way to get the file name. If you need a file, first write the input stream to a (temporary) file.

The SecurityException is throw when your temporary access was revoked. This happend for me on some files that I tried to read incorrectly before and specifically when the Intent was picked up in my Acticity's onNewIntent.