Why can't my JToolBar and JPanel coexist on the same JFrame

Question

I want my Jpanel to be just below my toolbar but the result will be my jpanel not appearing and if I also make my JPanel to have a borderlayout of page start the JFrame will only show the JPanel and not my toolbar. This is my code

package omok;

import java.awt.*;
import java.awt.event.*;
import java.net.URL;
import java.util.*;
import javax.swing.*;
public class Omok implements ActionListener {
    JFrame frame =new JFrame();
    public Omok() {
       JMenuBar menuBar=menubar();
       JToolBar toolBar=toolBar();
       JPanel panel=panel();
       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       frame.setSize(400,500);
       frame.getContentPane().setBackground(Color.ORANGE);
       frame.setLayout(new BorderLayout());
       frame.setJMenuBar(menuBar);
       frame.add(toolBar,BorderLayout.PAGE_START);
       frame.add(panel,BorderLayout.NORTH);
       frame.pack();
       frame.setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        
    }
private JMenuBar menubar() {
    JMenuBar menuBar = new JMenuBar();
    JMenu menu = new JMenu("Game");
    menu.setMnemonic(KeyEvent.VK_G);
    menu.getAccessibleContext().setAccessibleDescription("Game menu");
    menuBar.add(menu);
    JMenuItem menuItem = new JMenuItem("Play", KeyEvent.VK_P);
    menuItem.setAccelerator(KeyStroke.getKeyStroke(
       KeyEvent.VK_P, InputEvent.ALT_DOWN_MASK));
    menuItem.getAccessibleContext().setAccessibleDescription(
       "Play a new game");
    //menuItem.addActionListener(…);
    menu.add(menuItem);
    return menuBar;
}
private JToolBar toolBar() {
    ImageIcon icon=new ImageIcon("C:\\Users\\carlo\\Documents\\Adv OO Programming\\L\\OmokGUI\\res\\play.png");
    Image image=icon.getImage();
    Image newImg=image.getScaledInstance(20, 20, Image.SCALE_SMOOTH);
    icon=new ImageIcon(newImg);
    JToolBar toolBar = new JToolBar("Omok");
    JButton button = new JButton(icon);
    button.setPreferredSize(new Dimension(20,20));
    button.setToolTipText("Play a new game");
    button.setFocusPainted(false);
    toolBar.add(button);
    toolBar.setPreferredSize(new Dimension(30,30));
    return toolBar;

}
private JPanel panel() {
    JPanel panel=new JPanel();
    panel.setPreferredSize(new Dimension(40,40));
    panel.setBackground(Color.gray);
    return panel;
}

}

This is the result I get

Answer 1

As the BorderLayout JavaDocs state, "PAGE_START ... this is equivalent to NORTH" - so you're trying to place two components into the same position, BorderLayout will only allow a single component to exist at each of it's 5 available locations.

If you want both components in the NORTH position, then you'd need to use another container (like JPanel) to place them into and the place that container into the NORTH position.

This is often know as a compound layout.