BoringWindow

Code

import javax.swing.*;

public class BoringWindow extends JFrame
{
    public static void main ( String[] args )
    {
        JFrame f = new BoringWindow();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setSize(300, 200);
        f.setVisible(true);
    }
}

BoringWindow