IPtoName.java

import java.net.*;
public class IPtoName {
    public static void main(String args[]) {
        if (args.length == 0) {
            System.out.println("Pemakaian: java IPtoName <IP address>");
            System.exit(0);
        }
        String host = args[0];
        InetAddress address = null;
        try {
            address = InetAddress.getByName(host);
        } catch (UnknownHostException e) {
            System.out.println("invalid IP - malformed IP");
            System.exit(0);
        }
        System.out.println(address.getHostName());
    }
}