import javax.swing.*;  
public class SwingDemo
{ 
	public static void main(String[] args)
	{ 
		JFrame f=new JFrame();  //creating instance of JFrame
												  
		JButton b=new JButton("ok");  //creating instance of JButton 
		b.setBounds(130,100,100, 50);   //x axis, y axis, width, height  
												  
		f.add(b);    //adding button in JFrame 
												  
		f.setSize(350,350);   //400 width and 500 height 
		f.setLayout(null);     //using no layout managers  
		f.setVisible(true);    //making the frame visible
	} 
}

import javax.swing.*;
public class SwingDemo1 extends JFrame
{    
	JFrame f;
	SwingDemo1()
	{
		JButton b=new JButton("OK");             
		b.setBounds(130,100,100, 50);
												  
		add(b);             
		setSize(350, 350); 
		setLayout(null);
		setVisible(true);  
	} 
	public static void main(String[] args)
	{
		new SwingDemo1(); 
	}
}