public HadukiServer() {
        MainFrame frame = new MainFrame();
        // validate() ̓TCY𒲐
        // pack() ͗LȃTCYCAEgȂǂ擾
        if (packFrame) {
            frame.pack();
        } else {
            frame.validate();
        }

        // EBhE𒆉ɔzu
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        Dimension frameSize = frame.getSize();
        if (frameSize.height > screenSize.height) {
            frameSize.height = screenSize.height;
        }
        if (frameSize.width > screenSize.width) {
            frameSize.width = screenSize.width;
        }
        frame.setLocation((screenSize.width - frameSize.width) / 2,
                          (screenSize.height - frameSize.height) / 2);
        frame.setVisible(true);
    }