How can I generate labels and buttons in GUI?

Hello guys, Im new with Intellij and Java programming and I got a question.

Id like to generate number of i-checkboxes with different text each. How can i do that? I think that I just need a loop which would generate me those checkboxes but im not sure where to write in Intellij. I know that GUI is based on XML, and I have no idea where could i place such a loop to make everything visible etc. Also - if I want to create JLabel with text from other function, string... where can I do that? 

My code for this gui looks like this rn: 

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class DeleteSubjectMenu extends JDialog {
    private JPanel contentPane;
    private JButton buttonOK;
    private JButton buttonCancel;

    public DeleteSubjectMenu() {
        setContentPane(contentPane);
        setModal(true);
        getRootPane().setDefaultButton(buttonOK);
        buttonCancel.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                dispose();
            }
        });
    }

    public void main(String[] args) {
        DeleteSubjectMenu dialog = new DeleteSubjectMenu();
        dialog.pack();
        dialog.setVisible(true);
        System.exit(0);

    }
}