I am getting
open failed:
EACCES (Permission denied)
on the line OutputStream myOutput = new FileOutputStream
For anyone coming here from search results and are targeting Android 10: Android 10 (API 29) changes some permissions related to storage.
I fixed the issue when I replaced my previous instances of Environment.getExternalStorageDirectory() (which is deprecated with API 29) with context.getExternalFilesDir(null).
Note that context.getExternalFilesDir(type) can return null if the storage location isn't available, so be sure to check that whenever you're checking if you have external permissions.
Read more here.