SimpleFrameTest.java

import javax.swing.*;
public class SimpleFrameTest
{
public static void main (String[] args)
{
SimpleFrame frame =new SimpleFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);

}
}
class SimpleFrame extends JFrame
{
public SimpleFrame()
{
setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);

}
public static final int DEFAULT_WIDTH=300;
public static final int DEFAULT_HEIGHT=200;


}