我不能用键绑定来移动我的JLabel？

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class LabelMovementExample {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Label Movement Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 400);

        JPanel panel = new JPanel();
        panel.setLayout(null);

        JLabel label = new JLabel("Move me with arrow keys");
        label.setBounds(50, 50, 150, 30);

        panel.add(label);
        frame.add(panel);

        panel.setFocusable(true);
        panel.requestFocusInWindow();

        panel.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0), "up");
        panel.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0), "down");
        panel.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0), "left");
        panel.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0), "right");

        panel.getActionMap().put("up", new AbstractAction() {
            public void actionPerformed(ActionEvent e) {
                label.setLocation(label.getX(), label.getY() - 10);
            }
        });

        panel.getActionMap().put("down", new AbstractAction() {
            public void actionPerformed(ActionEvent e) {
                label.setLocation(label.getX(), label.getY() + 10);
            }
        });

        panel.getActionMap().put("left", new AbstractAction() {
            public void actionPerformed(ActionEvent e) {
                label.setLocation(label.getX() - 10, label.getY());
            }
        });

        panel.getActionMap().put("right", new AbstractAction() {
            public void actionPerformed(ActionEvent e) {
                label.setLocation(label.getX() + 10, label.getY());
            }
        });

        frame.setVisible(true);
    }
}