import javax.swing.*;
import java.awt.*;

public class GLayout {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Gribouille");
        frame.getContentPane().setLayout(new GridLayout(6, 3));

        for (int i = 0; i<15; i++) {
            frame.add(new JButton("Bouton " + i));
        }

        frame.setSize(800, 600);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    }
}