android - How to extract the file name from URI returned from Intent.ACTION_GET_CONTENT?

Question

I am using 3rd party file manager to pick a file (PDF in my case) from the file system.

This is how I launch the activity:

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType(getString(R.string.app_pdf_mime_type));
intent.addCategory(Intent.CATEGORY_OPENABLE);

String chooserName = getString(R.string.Browse);
Intent chooser = Intent.createChooser(intent, chooserName);

startActivityForResult(chooser, ActivityRequests.BROWSE);

This is what I have in onActivityResult:

Uri uri = data.getData();
if (uri != null) {
    if (uri.toString().startsWith("file:")) {
        fileName = uri.getPath();
    } else { // uri.startsWith("content:")

        Cursor c = getContentResolver().query(uri, null, null, null, null);

        if (c != null && c.moveToFirst()) {

            int id = c.getColumnIndex(Images.Media.DATA);
            if (id != -1) {
                fileName = c.getString(id);
            }
        }
    }
}

Code snippet is borrowed from Open Intents File Manager instructions available here:
http://www.openintents.org/en/node/829

The purpose of if-else is backwards compatibility. I wonder if this is a best way to get the file name as I have found that other file managers return all kind of things.

For example, Documents ToGo return something like the following:

content://com.dataviz.dxtg.documentprovider/document/file%3A%2F%2F%2Fsdcard%2Fdropbox%2FTransfer%2Fconsent.pdf

on which getContentResolver().query() returns null.

To make things more interesting, unnamed file manager (I got this URI from client log) returned something like:

/./sdcard/downloads/.bin

Is there a preferred way of extracting the file name from URI or one should resort to string parsing?

Answer 1

developer.android.com has nice example code for this: https://developer.android.com/guide/topics/providers/document-provider.html

A condensed version to just extract the file name (assuming "this" is an Activity):

public String getFileName(Uri uri) {
  String result = null;
  if (uri.getScheme().equals("content")) {
    Cursor cursor = getContentResolver().query(uri, null, null, null, null);
    try {
      if (cursor != null && cursor.moveToFirst()) {
        result = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
      }
    } finally {
      cursor.close();
    }
  }
  if (result == null) {
    result = uri.getPath();
    int cut = result.lastIndexOf('/');
    if (cut != -1) {
      result = result.substring(cut + 1);
    }
  }
  return result;
}