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

public class SimpleMultiThreadServer {
	public static void main(String args[]){	
			myServer ws = new myServer(args[0]);
			ws.start();
	}	
}	
	
	
class myServer extends Thread {
   myServer(String confpath) { ... } // constructors
   synchronized public static void Slog(String writeln) { ...} // use slog() to keep a log of all activities
   public void run() { // redefine run method for handling multiple clients...
      ServerSocket ss = new ServerSocket(PortNumber);
          myServer.slog("server started or not log... after conditional on ss"); 
      While (true) { //listen on the port for client connections
         Socket cs = ss.accept();  //client socket
                // can check at this point whether client is acceptable using IPaddresses in confFile
                // use cs.getInetAddress() and compare against your database in confFile
         ClientThread ct  = new ClientThread(confpath,cs); // create a client thread if client is acceptable
	 ct.start(); // start the thread to service the client
       }
}

class ClientThread extends Thread {
        String confpath;
	BufferedReader br;
	PrintWriter pw;
	Socket cs;
   ClientThread(String confpath,Socket cs){ // constructors
        this.confpath = confpath;  this.cs = cs;
        br = new BufferedReader(new InputStreamReader(cs.getInputStream()));
        pw = new PrintWriter(cs.getOutputStream(),true);
        }
        
   public void run() { //rewrite run() method for clientThread
      ...
      readin = br.readLine(); // read from client
      ...
      writeout = new String("First userFriendly message sent from the server to client");
      myServer.Slog(writeout);
      pw.print(writeout+"\r\n");  // write to client
      ...
      br.close();
      pw.close();
      cs.close();
      }