Java Swing - 如何自定义JOptionPane.showMessageDialog图标

Here is a variant that uses a URL:



import java.net.URL;

import javax.swing.ImageIcon;
import javax.swing.JOptionPane;

public class Main
{
    public static void main(String[] args) throws Exception
    {
        final ImageIcon icon = new ImageIcon(new URL("http://www.w3cschool.cn/style/download.png"));
        JOptionPane.showMessageDialog(null, "Blah blah blah", "About", JOptionPane.INFORMATION_MESSAGE, icon);
    }
}