private static List <File> directoryFiles(String path, String extension) {
		List <File> allFiles = new ArrayList <File> ();
		allFiles.add(new File(path));
		int index = 0;
		while (index != allFiles.size()) {
			File currentFile = allFiles.get(index);
			if (currentFile.isDirectory()) {
				allFiles.remove(index);
				for (File newFile : currentFile.listFiles())
					allFiles.add(newFile);
			} else if (!currentFile.getPath().endsWith(extension))
				allFiles.remove(index);
			else index++;
		}
		return allFiles;
	}