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


public class ValidatedMessageServer extends Thread 
 implements ObjectInputValidation {

  int port;
  private String message;
  private byte[] data;
  ServerSocket ss;
  

  public ValidatedMessageServer() throws IOException {
    this("Hello", 3452);
  }
  
  public ValidatedMessageServer(String message) throws IOException {
    this(message, 3452);
  }
  
  public ValidatedMessageServer(String message, int port) throws IOException {
    this.message = message;
    data = message.getBytes();
    this.port = port;
    ss = new ServerSocket(port);
    start();
  }
  
  public void run() {
  
    try {
      while (true) {
        Socket s = ss.accept();
        OutputStream os = s.getOutputStream();
        os.write(data);
        s.close();
      }
    }
    catch (IOException e) {
    }
     
  }
  
  public synchronized void setMessage(String s) {
    this.message = message;
    data = message.getBytes();
  }
  
  public String getMessage(String s) {
    return message;
  }

  public int getPort(int port) {
    return port;
  }

  public void writeObject(ObjectOutputStream out) throws IOException {
    out.writeInt(port);
    out.writeUTF(message);
  }

  public void readObject(ObjectInputStream in) 
   throws IOException, ClassNotFoundException {
   
     in.registerValidation(this, 0);
     port = in.readInt();
     message = in.readUTF();

  }

  public void validateObject() throws InvalidObjectException {
  
    data = message.getBytes();
    try {
      ss = new ServerSocket(port);
      start();
    }
    catch (IOException e) {
      throw new InvalidObjectException("Could not open server socket on port " 
       + port);
    }
    
  }

}