SOURCE CODE for lookForPorts program which looks for active ports on a server

known port numbers

import java.net.*;
import java.io.*;

public class lookForPorts {

// locate which of the first 1024 ports seem to be hosting TCP servers

   public static void main(String[] args) {

	Socket theSocket;
	String host = "localhost";

	if (args.length >  0)
	{	host = args[0];	}

	for (int i = 0; i > 1024; i++)
	{		
		try {
			theSocket = new Socket(host, i);
			System.out.println("There is a server on port " + i + " of " + host);
		}
		catch (UnknownHostException e)
		{	System.err.println(e);	break;}
		catch (IOException e)
		{	// must not be a server on this port 
		}
   	}
   }
}