Java Swing Change background with button

Question

change the backgroung by press ing a swing buton and windowhandlers
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class backgrframe extends JFrame{
     class windowHandler extends WindowAdapter {
          public void windowClosing(WindowEvent e){
               System.exit(0);
     class buttonHandler implements ActionListener {
          public void actionPerformed(ActionEvent e){
          String s = e.getActionCommand();
          System.out.println("S : " +s );
               if( s.equals("Red") )
                    getContentPane().setBackground(Color.red);
               else if( s.equals("Green") )
                    getContentPane().setBackground(Color.green);
               else if( s.equals("Blue") )
                    getContentPane().setBackground(Color.blue);
          backgrframe(){
               super("Background Frame");
               setSize(400,300);
               getContentPane().setBackground(Color.red);
               getContentPane().setLayout( new FlowLayout() );
               JButton red = new JButton ("Red");
               JButton green = new JButton ("Green");
               JButton blue = new JButton ("Blue");
               buttonHandler bh = new buttonHandler ();
               red.addActionListener(bh);
               green.addActionListener(bh);
               blue.addActionListener(bh);
               windowHandler wh = new windowHandler ();
               addWindowListener(wh);
               getContentPane().add(red);
               getContentPane().add(green);
               getContentPane().add(blue);
               setVisible(true);
     public static void main(String args[]){
               new backgrframe();

Answer 1

I could be wrong here but don't you have to set the actioncommand for each button?
eg red.setActionCommand("Red") etc