import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class Ping {
    public static void main(String[] args) throws IOException {
        try {
            String hostname = args[0];
            int timeout = (args.length > 1)?Integer.parseInt(args[1]):2000;
            InetAddress[] addresses = InetAddress.getAllByName(hostname);
            for(InetAddress address : addresses) {
                if (address.isReachable(timeout))
                    System.out.printf("%s is reachable%n", address);
                else
                    System.out.printf("%s could not be contacted%n", address);
            }
        }
        catch (UnknownHostException e) {
            System.out.printf("Unknown host: %s%n", args[0]);
        }
        catch(IOException e) { System.out.printf("Network error: %s%n", e); }
        catch (Exception e) { 
            // ArrayIndexOutOfBoundsException or NumberFormatException
            System.out.println("Usage: java Ping <hostname> [timeout in ms]");
        }
    }
}