Java FocusTraversalPolicy get previous focusable component

import java.awt.Component;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.FocusTraversalPolicy;
import java.awt.KeyboardFocusManager;

import javax.swing.JButton;
import javax.swing.JFrame;

public class Main {
   public static void main(String[] argv) {
      JFrame frame = new JFrame();
      JButton component1 = new JButton("1");
      JButton component2 = new JButton("2");
      JButton component3 = new JButton("3");

      frame.setLayout(new FlowLayout());
      frame.add(component1);/*from   w  ww .  j a v  a 2s . c  o  m*/
      frame.add(component2);
      frame.add(component3);

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

      System.out.println(findPrevFocus().getName());
   }

   public static Component findPrevFocus() {
      Component c = KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner();
      Container root = c.getFocusCycleRootAncestor();

      FocusTraversalPolicy policy = root.getFocusTraversalPolicy();
      Component prevFocus = policy.getComponentBefore(root, c);
      if (prevFocus == null) {
         prevFocus = policy.getDefaultComponent(root);
      }
      return prevFocus;
   }
}