title: Can not open downloaded file by it uri
body: <p>Actually, I use intent to select a <strong>pdf</strong> file. And I get uri and its path (getPath()) in onActivityResult.
  The path I got is <code>"content://com.android.providers.downloads.documents/document/2816"</code> which is not as a usual path of pdf file.</p>
  
  <p>Can any one help me to solve it to ensure the uri provided can be convert to path of the pdf file I had chosen?</p>
  
  <p>Thank you for your help!</p>