Java SpringLayout class

import java.awt.Container; 
import javax.swing.JFrame; 
import javax.swing.SpringLayout; 
import javax.swing.JButton; 

public class Main { 
    public static void main(String[] args) { 
        JFrame frame = new JFrame("Simplest SpringLayout"); 
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
        Container contentPane = frame.getContentPane(); 

        // Set the content pane's layout as SpringLayout  
        SpringLayout springLayout = new SpringLayout(); 
        contentPane.setLayout(springLayout); 

        // Add two JButtons to the content pane 
        JButton b1 = new JButton("Button 1"); 
        JButton b2 = new JButton("Little Bigger Button 2"); 
        contentPane.add(b1); /*  w ww .  ja  v  a  2s  .  co m*/
        contentPane.add(b2); 

        frame.pack(); 
        frame.setVisible(true); 
    } 
}