java Swing 练习

import javax.swing.JFrame; public class Swingtest {    static final int WIDTH = 500;    static final int HEIGHT = 500;    public static void main(String[] args){        JFrame jf = new JFrame("hello,Swinghahahahahah !");        jf.setSize(WIDTH,HEIGHT);        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        jf.setVisible(true);    }}