java IP 地址正则式

private static final Pattern p = Pattern.compile("((\\d{1,2}|1\\d\\d|2[0-4]\\d|25[0-5])\\.(\\d{1,2}|1\\d\\d|2[0-4]\\d|25[0-5])\\.(\\d{1,2}|1\\d\\d|2[0-4]\\d|25[0-5])\\.(\\d{1,2}|1\\d\\d|2[0-4]\\d|25[0-5]))");public static void main(String[] arg) {Matcher matcher = p.matcher("127.0.0.1");if (matcher.matches()) {System.out.println(matcher.group(1));} else {System.out.println("no mathch");}}