How to align swing buttons vertically ?

Hello !

I want to create a swing application with a main frame and a panel
containing vertically aligned buttons at the right side. Here is the code:

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

public class TestViewer {

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new ViewerFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setSize(800, 600);
                frame.setVisible(true);
            }
        });
    }
}

class ViewerFrame extends JFrame {

    public ViewerFrame() {
        getContentPane().add(new JPanel(), BorderLayout.CENTER);
        getContentPane().add(createBtnPanel(), BorderLayout.EAST);
    }

    private JPanel createBtnPanel() {
        JPanel btnPanel = new JPanel();

        btnPanel.setLayout(new GridLayout(0, 1));

        btnPanel.add(new JButton("Button 1"));
        btnPanel.add(new JButton("Button 2"));
        btnPanel.add(new JButton("Long Button 3"));
        btnPanel.add(new JButton("Button 4"));
        btnPanel.add(new JButton("Button 5"));

        // Trick here !
        // I put the btnPanel at the NORTH of a "dummy" panel to have
        // the correct button sizes !!!
        // Other solutions ??
        JPanel dummyPanel = new JPanel();
        dummyPanel.setLayout(new BorderLayout());
        dummyPanel.add(btnPanel, BorderLayout.NORTH);

        return dummyPanel;
    }
}

It works, but is there an other way to avoid the dummyPanel trick ?

Thanks a lot !

Olivier