FlowLayout type Frame in Java

import java.awt.Color;
import javax.swing.*;
public class FlowLayout
{
JFrame f = new JFrame("FlowLayout");
JPanel p = new JPanel();
JButton b1 = new JButton("button1");
JButton b2 = new JButton("button2");
JButton b3 = new JButton("button3");
public static void main(String ar[])
{
FlowLayout fl = new FlowLayout();
fl.show();
}
public void show()
{
p.add(b1);
p.add(b2);
p.add(b3);
p.setBackground(Color.BLUE);
f.getContentPane().add(p);
f.setSize(500,500);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
}