processDirectory(new File("c:\\"))

import java.io.File;

object SolutionXX extends Application {

def processFile(file : File) = { println(file.getName) }

def processDirectory(dir : File) : Unit =
{
for (file <- dir.listFiles) { processFile(file) ; if (file.isDirectory) processDirectory(file) }
}

processDirectory(new File("c:\\"))
}