code: public void splash() {
  		frame = shadowBorder ? new ShadowBorderFrame() : new JFrame();
  		if (isRootFrame())
  			JOptionPane.setRootFrame(frame);
  
  		frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
  		frame.setUndecorated(true);
  
  		frame.setTitle(loadFrameTitle());
  		frame.setIconImage(loadFrameIcon());
  
  		Component content = createContentPane();
  		if (content != null) {
  			frame.getContentPane().add(content);
  		}
  		frame.pack();
  		WindowUtils.centerOnScreen(frame);
  		frame.setVisible(true);
  	}
docs: Creates and displays an undecorated, centered splash screen containing
  the component provided by {@link #createContentPane()}. If this instance
  has been provided with a {@link MessageSource}, it will be used to
  retrieve the splash screen's frame title under the key
  {@value #SPLASH_TITLE_KEY}.