Formatting IP:Port string to

Question

I\'m trying to make a little chat program for experimentation, but seeing as I\'m not the best Java programmer, I don\'t know how to separate a port from an IP where they are bo

Answer 1

to validate IP:PORT format you may try this:

public class Validator {

    private static final String IP_PORT_PATTERN =
            "^([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
                    "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
                    "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
                    "([01]?\\d\\d?|2[0-4]\\d|25[0-5]):" +
                    "([1-9][0-9]{0,3}|[1-5][0-9]{4}|6[0-4][0-9]{3}|65[0-4][0-9]{2}|655[0-2][0-9]|6553[0-5])$";

    private static final Pattern PATTERN;

    static {
        PATTERN = Pattern.compile(IP_PORT_PATTERN);
    }

    public static boolean validate(final String s) {
        return PATTERN.matcher(s).matches();
    }

}

thanks to frb and mkyong :)

and to separate ip and port :

public static void main(String args[]) {
    String s = "127.0.0.1:8080";
    if (validate(s)) {
        String ip = s.substring(0, s.indexOf(':'));
        int port = Integer.parseInt(s.substring(s.indexOf(':') + 1));
        System.out.println(ip);
        System.out.println(port);
    } else {
        System.out.println("invalid format");
    }
}