Socket - livro deitel

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.(Event).*;
import javax.swing.*;

public class Servidor extends JFrame{

private JTextField enterField;
private JTextArea displayArea;
private ObjectOutputStream output;
private ObjectInputStream input;
private ServerSocket server;
private Socket connection;
private int cont=1;

public Servidor(){
super("Server");
Container container = getContentPane();
enterField = new JTextField();
enterField.setEnabled(false);

enterField.addActionListener(
		
		new ActionListener(){
			public void actionPerformed(ActionEvent event){
				sendData( event.getActionCommand());
			}
		} 
	);
container.add(enterField, BorderLayout.NORTH);
displayArea= new JTextArea();
container.add(new JScrollPane(displayArea));

setSize(300, 150);
setVisible(true);
}

public void runServidor(){
	try {
		server = new ServerSocket(5000, 100);
		while (true){
			waitForConnection();
			getStreams();
			processConnection();
			closeConnection();
			++cont;
		}
	}	
catch (EOFException eofExeption){
	System.out.println("conexão terminada do cliente");
}

catch (IOException ioExeption){
	ioExeption.printStackTrace();
}
	}
private void waitForConnection() throws IOException{
   displayArea.setText("esperando pela conexão\n");
   connection = server.accept();
   displayArea.append("conexão" + cont + "recebida de: " + 
		   	connection.getInetAddress().getHostName() );
}
private void getStreams() throws IOException{
output = new ObjectOutputStream(
		connection.getOutputStream() );

output.flush();

input = new ObjectInputStream(
		connection.getInputStream() );
displayArea.append("\nGot I/O streams\n");
}
private void processConnection()throws IOException{
	String message = "SERVER>>> connetction successful";
	output.writeObject(message);
	output.flush();
	enterField.setEnabled(true);
	do {
		try{
			message = (String) input.readObject();
			displayArea.append("\n" + message);
			displayArea.setCaretPosition(
					displayArea.getText().length());
			}
		catch (ClassNotFoundException classNotFoundException){
			displayArea.append("recebeu um tipo de obijeto desconhecido");
		}
	} while (!message.equals("client>>> terminate"));
}
private void closeConnection() throws IOException{
	displayArea.append("terminou de usar conexão");
	enterField.setEnabled(false);
	output.close();
	input.close();
	connection.close();
	}
private void sendData( String message ){
	try{
		output.writeObject("server>>>" + message);
		output.flush();
		displayArea.append("\nserver>>>" + message);
	}
	catch (IOException ioExeption){
		displayArea.append("\nerro ao escrever objeto");
	}
}
public static void main(String args[]){
	Servidor application = new Servidor();
	application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	application.runServidor();
	}
}