add random number of buttons

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public final class GUI extends JFrame
{
    private JButton submit;
    private JPanel btnList;

    public GUI()
    {
        setLayout(new BorderLayout());
        JPanel content = new JPanel();
        content.setLayout(new BorderLayout());
        content.setPreferredSize(new Dimension(200, 300));
        this.getContentPane().add(content);

        btnList = new JPanel();
        btnList.setLayout(new BoxLayout(btnList, BoxLayout.PAGE_AXIS));

        submit = new JButton("Get Random");


        //Add Components to this container
        content.add(submit, BorderLayout.NORTH);
        content.add(btnList, BorderLayout.CENTER);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
    }

    private void makeButtons(int number)
    {
        validate();
    }

    public static void main(String[] args)
    {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                //Create and set up the content pane.
                GUI frame = new GUI();
                frame.setVisible(true);
            }
        });
    }
}