public static String camel4underline(String param) {
		Pattern p = Pattern.compile("[A-Z]");
		if (param == null || param.equals("")) {
			return "";
		}
		StringBuilder builder = new StringBuilder(param);
		Matcher mc = p.matcher(param);
		int i = 0;
		while (mc.find()) {
			builder.replace(mc.start() + i, mc.end() + i, "_" + mc.group().toLowerCase());
			i++;
		}

		if ('_' == builder.charAt(0)) {
			builder.deleteCharAt(0);
		}
		return builder.toString();
	}