CODEWITHSUNDEEP
androidandroid-5.0-lollipopandroid-6.0-marshmallowandroid-filestorage-access-framework
0xC0DED00D
0xC0DED00D

Reputation: 20348

Get File Uri from Document Id in Storage Access Framework

I am using directory selection as described in this Google Sample. 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 COLUMN_DOCUMENT_ID on the Cursor Query. I am interested in the file URI of the children instead. When I use ACTION_OPEN_DOCUMENT instead of ACTION_OPEN_DOCUMENT_TREE, I get the child uri easily which is just obtained from adding a %2Fchildfile.extention (%2F is just a forward slash). So I tried to get child file uri using the following code - 

uri = Uri.parse(docUri.toString()+"%2F"+fileName);

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.

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.

PS: I am currently checking it in Marshamallow.

Upvotes: 1

Views: 2649

Answers (1)

0xC0DED00D
0xC0DED00D

Reputation: 20348

After reading the doc and trying out certain examples, I got the following way to get a single file Uri from a selected docUri/treeUri 

uri = DocumentsContract.buildDocumentUriUsingTree(docUri,docId);

And then you can convert it anytime into a DocumentFile using following code - 

DocumentFile file = null;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
   if (DocumentsContract.isDocumentUri(context, uri)) {
       file = DocumentFile.fromSingleUri(context, uri);
   } else {
       file = DocumentFile.fromTreeUri(context, uri);
   }
}

fromTreeUri() method is required for the selected Tree Directory, so that it can return true on file.exists() method call.
You need to remember that if the children contain any directory, then you can't call childDirectory.listFiles() on it. It'll give UnsupportedOperationException, because you don't have permission to access the child directory's file. Read more about this here.

Upvotes: 2

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