Client-server на java

package educ.mark;
 
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
 
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
 
public class server extends JFrame implements Runnable{
    JTextField t1;
    JButton b1;
    Socket connection;
    ObjectInputStream a;
    static ObjectOutputStream b;
    public static void main(String [] args){
    new Thread(new server("test")).start();
    server r=new server("test");
    r.setSize(300,300);
    r.setVisible(true);
        
    }
    public server(String name){
    super(name);
    setLayout(new FlowLayout());
    t1=new JTextField(10);
    b1=new JButton("send");
    add(t1);
    add(b1);
    b1.addActionListener(new ActionListener(){
 
        @Override
        public void actionPerformed(ActionEvent arg0) {
        if(arg0.getSource()==b1){
            data(t1.getText());
        }
            
        }
        
    });
    }
    public void run() {
        try {
        connection=new Socket(InetAddress.getByName("127.0.0.1"),2556);
        a=new ObjectInputStream(connection.getInputStream());
            b=new ObjectOutputStream(connection.getOutputStream());
        JOptionPane.showMessageDialog(null, (String)(a.readObject()));
    } catch (Exception e) {
        e.printStackTrace();}}
        private static void data(Object obj){
            try{
                b.flush();
                b.writeObject(obj);
            }catch(Exception e){}
        }
    }

import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
 
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
 
public class serv implements Runnable {
    static private ServerSocket server;
    JTextField t1;
    JButton b1;
    Socket connection;
    ObjectInputStream a;
    static ObjectOutputStream b;
 
    @Override
    public void run() {
        try {
            server=new ServerSocket(5677,10);
            connection=server.accept();
            a=new ObjectInputStream(connection.getInputStream());
            b=new ObjectOutputStream(connection.getOutputStream());
            b.writeObject("=:"+a.readObject());
        } catch (Exception e) {
            e.printStackTrace();}}
        
    }