Hello World using the JOptionPane

HelloGUI

/***********************************************
* HelloGUI.java
* Aaron P. Clark
*
* One of the last programs of the chapter.  Exhibits
* the use of the JOPtionPane GUI
***********************************************/

import javax.swing.JOptionPane;
public class HelloGUI
{
	public static void main(String[] args)
	{
		JOptionPane.showMessageDialog(null, "Hello, World!");
	}
}

You should consider adding SwingUtilities.invokeAndWait() to ensure the call makes it on the Event Dispatch Thread.

https://gist.github.com/tresf/6e2f0fb8db69457ddc4e05a41b7c7c27