15.2

import java.awt.Color;
import java.awt.Graphics;
import java.awt.GridLayout;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Test_15 extends JFrame{
    public Test_15(){
        setLayout(new GridLayout(1,2,5,5));
        add(new OvalButton("OK"));
        add(new OvalButton("CANCEL"));
    }
    
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Test_15 t = new Test_15();
        t.setTitle("test");
        t.setSize(400,100);
        t.setLocationRelativeTo(null);
        t.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        t.setVisible(true);
    }

}

class OvalButton extends JButton{
    public String str;
    public OvalButton(String str){
        this.str = str;
    }
    protected void paintComponent(Graphics g){
        super.paintComponent(g);
        
        int width = getWidth();
        int height = getHeight();
        g.drawString(str, width/2, height/2);
        g.drawOval((int)(0.1*width), (int)(0.1*height), (int)(0.8*width), (int)(0.8*height));
    }
}