Create Button on Frame

import javax.swing.*;

class Button extends JFrame
{
   JButton b1;
 
   Button()
   {    
      add(b1=new JButton("ok"));
      b1.setBounds(60,60,50,50);
   }
  
   public static void main(String[] args) 
   {
      JFrame win = new Button();
   
      win.setTitle("Button");
      win.setSize(200,200);
      win.setLayout(null);
      win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      win.setVisible(true);
   }  
}

Output