FileVisitor not behaving as expected

I have been trying to use a class that implements FileVisitor and simply copies a directory in preVisitDirectory, moves the files, and deletes the directory in `postVisitDirectory. This works without any problems.

The problem occurs when I try to implement a conditional: if(Files.list(dir).findAny().isEmpty())

All but the shallowest subdirectories persist in the original directory. The target directory is filled out 100% correctly. No error is thrown.

If I use skip(1) in the stream of the conditional, a DirectoryNotEmptyException is thrown. *on the delete line.*Functionality is incorrect, i.e., the same as if I used the conditional without skip.

If I do a printout with Files.list(dir).forEach(System.out::println);, functionality is incorrect and the exception is thrown, again on the delete line

Another human thinks functionality was not as intended because this:

'System.out.println(dir + " : ");
Files.list(dir).forEach(System.out::println);'

Outputs:

> E:\EncrypterTest\TopSecret\NestedFolder\DoublyNestedFolder\TriplyNestedFolder:
> E:\EncrypterTest\TopSecret\NestedFolder\DoublyNestedFolder:
> E:\EncrypterTest\TopSecret\NestedFolder\DoublyNestedFolder\TriplyNestedFolder
> E:\EncrypterTest\TopSecret\NestedFolder :
> E:\EncrypterTest\TopSecret\NestedFolder\DoublyNestedFolder

Where TriplyNestedFolder is the deepest folder in the directory. Remember, TriplyNestedFolder is being deleted when the code is complete. So are the other 2 if I don't check if they are empty.

So to recap it seems like:

1. The deepest directory is being accessed first (as expected), but despite .delete being called on it, it still exists for the purpose of the .delete in it's parent directory.
2. It is deleted after code completes
3. Parent directories are all deleted as well with no exception thrown
4. Adding a conditional as shown above causes copies of all but the deepest directory to remain
5. Adding a .skip(1) in the files stream causes functionality from #4, but produces DirectoryNotEmptyException
6. Adding a printout causes the same functionality and exception from #5
7. Exact same behavior occurs with or without files in the directories

I'm hoping this will be something obvious to someone here, but I'm at a loss. Thanks in advance for any help. If you need any more information/code please ask.

Javadoc of Files.list(Path dir) says:

> Return a lazily populated Stream, the elements of which are the entries in the directory. [...]
>
> [...]
>
> The returned stream encapsulates a DirectoryStream. If timely disposal of file system resources is required, the try-with-resources construct should be used to ensure that the stream's close method is invoked after the stream operations are completed.
>
> [...]

This means that the returned stream keeps an open OS directory handle, which on Windows may prevent the directory from being deleted.

Correct use of Files.list() is:

boolean isEmpty;
try (Stream<Path> pathStream = Files.list(dir)) {
    isEmpty = pathStream.findAny().isEmpty();
}
if (isEmpty) {
    // We can delete the directory here, since we've now released
    // the resources used by the stream, i.e. we've closed the handle
}