Java Swing - 如何将光标更改为点击JFrame

import java.awt.Cursor;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main extends JFrame {

  private JPanel pane;

  public Main() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    addMouseListener(getListener());
    setSize(200, 200);
    pane = (JPanel) getContentPane();
    setVisible(true);
  }

  private MouseListener getListener() {
    return new MouseAdapter() {
      @Override
      public void mousePressed(MouseEvent e) {
        super.mousePressed(e);
        pane.setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
      }
      @Override
      public void mouseReleased(MouseEvent e) {
        super.mouseReleased(e);
        pane.setCursor(Cursor.getDefaultCursor());
      }
    };
  }
  public static void main(String... s) {
    new Main();
  }
}