Java Swing - 如何在标题中使用JOptionPane.showInputDialog的自定义图标

import java.awt.Image;
import java.net.URL;

import javax.imageio.ImageIO;
import javax.swing.JDialog;
import javax.swing.JOptionPane;

public class Main {

  public static void main(String[] args) throws Exception {
    JOptionPane jop = new JOptionPane("Message", JOptionPane.QUESTION_MESSAGE,
        JOptionPane.DEFAULT_OPTION);

    JDialog dialog = jop.createDialog("Dialog Title");

    Image image = ImageIO.read(new URL(
        "http://www.w3cschool.cn/style/download.png"));
    dialog.setIconImage(image);
    dialog.setVisible(true);
  }
}