java 文件重命名

private static String rename(String name) {

		Long now = Long.parseLong(new SimpleDateFormat("yyyyMMddHHmmss").format(new Date()));
		Long random = (long) (Math.random() * now);
		String fileName = now + "" + random;

		if (name.indexOf(".") != -1) {
			fileName += name.substring(name.lastIndexOf("."));
		}

		return fileName;
	}