Interface graphique java

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

public class HelloWorldSwing 
{
    public static void main(String[] args) 
    {
        JFrame frame = new JFrame("First Swing");
        frame.setSize(250,100);
        frame.add(new JLabel("Hello World!", JLabel.CENTER));
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}