Wilson Wilson - 1 month ago 50
Android Question

File exists and IS directory, but listFiles() returns null

The documentation for

suggests that
null
will ONLY be returned in the case that the file calling it is not a directory.

I have the following:

String dir = "/storage/emulated/0";
File f = new File(dir);
Log.v("Files",f.exists()+"");
Log.v("Files",f.isDirectory()+"");
Log.v("Files",f.listFiles()+"");


The log reads:

true
true
null


For some reason,
listFiles(
) is returning
null
even though the
File
is recognized as a valid directory. I'm not super familiar with Android file hierarchy behavior, so I would guess the problem lies in there.

For reference, I'm debugging on my Moto X, and results are the same whether the phone is plugged in to my computer or not - so I don't think it has to do with mounting when plugged in.

Answer

For those with this problem, add this to AndroidManifest.xml:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

Problem solved :D

EDIT: If this does not work just make sure if path is correct