一道简单的图形题疑问

大家好，这是java2核心思想的一道例题，书中说点击按钮以后会变颜色，并且出现一句话："Set panel color to" + name.toLowerCase()，我把程序打出来，只能变颜色，那句话显示不出来，程序没检查出来哪不对，请高手帮忙解答
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;public class ActionTest
{
public static void main(String[] args)
{
ActionFrame frame = new ActionFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}class ActionFrame extends JFrame
{
public ActionFrame()
{
setTitle("ActionTest");
setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);
ActionPanel panel = new ActionPanel();
add(panel);
} public static final int DEFAULT_WIDTH = 300;
public static final int DEFAULT_HEIGHT = 200;
}class ActionPanel extends JPanel
{
public ActionPanel()
{
Action yellowAction = new ColorAction("Yellow",new ImageIcon("yellow-ball.gif"),Color.YELLOW);
Action blueAction = new ColorAction("Blue",new ImageIcon("blue-ball.gif"),Color.BLUE);
Action redAction = new ColorAction("Red",new ImageIcon("red-ball.gif"),Color.RED);
add(new JButton(yellowAction));
add(new JButton(blueAction));
add(new JButton(redAction));
InputMap imap = getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
imap.put(KeyStroke.getKeyStroke("ctrl Y"),"panel.yellow");
imap.put(KeyStroke.getKeyStroke("ctrl B"),"panel.blue");
imap.put(KeyStroke.getKeyStroke("ctrl R"),"panel.red");
ActionMap amap = getActionMap();
amap.put("panel.yellow",yellowAction);
amap.put("panel.blue",blueAction);
amap.put("panel.red",redAction);
} public class ColorAction extends AbstractAction
{
public ColorAction(String name,Icon icon,Color c)
{
putValue(Action.NAME,name);
putValue(Action.SMALL_ICON,icon);
putValue(Action.SHORT_DESCRIPTION,"Set panel color to" + name.toLowerCase());     /*就是这句显示不出来*/
putValue("color",c);
} public void actionPerformed(ActionEvent event)
{
Color c = (Color)getValue("color");
setBackground(c);
}
}
}