import java.awt.BorderLayout;

import java.awt.EventQueue;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.border.EmptyBorder;

import javax.swing.JButton;

import java.awt.Font;

import java.awt.event.ActionListener;

import java.awt.event.ActionEvent;

public class TicTacToe extends JFrame {

private boolean isX = false;

JButton oneBt = new JButton("");

JButton twoBt = new JButton("");

JButton threeBt = new JButton("");

public static void main(String[] args) {

TicTacToe frame = new TicTacToe();

frame.setVisible(true);

}

/**

* Create the frame.

*/

public TicTacToe() {

getContentPane().setFont(new Font("Tahoma", Font.BOLD, 18));

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setBounds(100, 100, 450, 300);

this.getContentPane().setLayout(null);

oneBt.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

printXorZero(oneBt);

}

});

oneBt.setBounds(35, 57, 89, 42);

getContentPane().add(oneBt);

twoBt.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

printXorZero(twoBt);

}

});

twoBt.setBounds(153, 57, 89, 42);

getContentPane().add(twoBt);

threeBt.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

printXorZero(threeBt);

}

});

threeBt.setBounds(252, 57, 89, 42);

getContentPane().add(threeBt);

}

private void printXorZero(JButton btObject){

if(btObject.getText().trim().length()==0){

if(isX){

btObject.setText("X");

}

else

{

btObject.setText("0");

}

isX = !isX;

}

}

}