Get File Uri from Document Id in Storage Access Framework
<p>I am using directory selection as described in this <a href="https://github.com/googlesamples/android-DirectorySelection" rel="nofollow">Google Sample</a>. It does provide file name and mime type of the children of the selected directory. I can get Document ID of the file too, if I use <code>COLUMN_DOCUMENT_ID</code> on the Cursor Query. 
I am interested in the file URI of the children instead. When I use <code>ACTION_OPEN_DOCUMENT</code> instead of <code>ACTION_OPEN_DOCUMENT_TREE</code>, I get the child uri easily which is just obtained from adding a <code>%2Fchildfile.extention</code> (%2F is just a forward slash). So I tried to get child file uri using the following code - </p>

<pre><code>uri = Uri.parse(docUri.toString()+"%2F"+fileName);
</code></pre>

<p>I got the file name, however when I run exists() method on it (By converting it into DocumentFile), it returns false. That means, either I don't have the permission of the file or it's not the correct way to get children uri.  </p>

<p>Am I missing something here or is there any other way I can select a folder and get file uri of all of it's children easily.</p>

<p>PS: I am currently checking it in Marshamallow.</p>