例如，这个代码一夜之间就停止工作了

package flap;

import javax.swing.*;
public class Flappy {

    public static flap.Flappy flap;

    public final int WIDTH = 400,HEIGHT = 800;

    public Flappy()
    {
        JFrame frame = new JFrame("Flappy");
        frame.setDefaultCloseOpperation(JFrame.EXIT_ON_CLOSE);

    }

}