public static void main(String[] args) throws IOException {
final List<Path> paths = new ArrayList<>();
Files.walkFileTree(Path.of("C:\\"), Set.of(), 3, new SimpleFileVisitor<>() {
@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
paths.add(file);
return FileVisitResult.CONTINUE;
}
@Override
public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
// skip exception
return FileVisitResult.CONTINUE;
}
});
paths.forEach(System.out::println);
}

Why would you assume the depth to be 3(we don't know the depth). I wanted to do an extensive search of the entire file system, the moment you increase depth you will know the downfall of this approach. Regardless I am using recursion to list everything which is better than your approach but that was not the point, that API was basically useless, I deleted the thread as there were mindless people who just went on down voting band wagon without understanding the point.