java swing 基础

1.一个只有一个lable的界面

import javax.swing.JFrame;
import javax.swing.JLabel;

public class reading extends JFrame    
{
    public static void main(String[] args)
    {
        new reading();
    }
    reading() {
        JLabel jlbHelloWorld = new JLabel("Hello World");
        add(jlbHelloWorld);
        this.setSize(100, 100);
        setVisible(true);
    }
}http://www.javabeginner.com/java-swing/java-swing-tutorial