gistfile1.java

File films = new File("x:/films");
File dir;

for (File fic : films.listFiles()) {
	if (fic.isFile()) {
		dir = new File(films, fic.getName().substring(0, fic.getName().lastIndexOf(".")));
		dir.mkdir();
		fic.renameTo(new File(dir, fic.getName()));
	}
}