private static String[] parseExtensions(String extensions) {
		if (extensions == null || extensions.length() == 0)
			return null;
		final String[] exts = extensions.split(",");
		for (int j = 0; j < exts.length; ++j) {
			exts[j] = exts[j].trim();
			if (exts[j].length() > 0 && exts[j].charAt(0) != '.')
				exts[j] = '.' + exts[j];
		}
		return exts;
	}