用Swing写的简易Hello World

package JavaPractice;import javax.swing.*;public class HelloWorldSwing{public void HelloWorldJFrame(){JFrame hws = new JFrame("Hello World Swing");JLabel hw = new JLabel("Hello World!");hws.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);hws.setVisible(true);hws.setSize(320, 240);hws.getContentPane().add(hw);hw.setHorizontalAlignment(SwingConstants.CENTER);}public static void main(String args[]){new HelloWorldSwing().HelloWorldJFrame();}}