DialogTest.java

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

public class DialogTest {
    public static void main(String[] args) {
        DemoDialog test = new DemoDialog(null, 1);
        test.setLocation(0,0);
        test.setVisible(true);
    }

    private static class DemoDialog extends JDialog{
        private int num;
        private JButton button;
        private JPanel mainPanel;

        public DemoDialog(Window owner, int num) {
            super(owner, "Dialog #" + num , ModalityType.APPLICATION_MODAL);

            button = new JButton("ok");
            button.addActionListener(buttonAction);
            mainPanel = new JPanel();
            mainPanel.add(button);
            getContentPane().add(mainPanel);
            setSize(200, 100);

            this.num = num;
        }
        private ActionListener buttonAction = new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                if(num == 1) {
                    DemoDialog test2 = new DemoDialog(null, 2);
                    test2.setLocation(0,200);
                    test2.setVisible(true);
                }
                // Uncomment to fix issue
//                try {
//                    Thread.sleep(500);
//                } catch (InterruptedException ex) {
//                    throw new RuntimeException(ex);
//                }
                setVisible(false);
                System.out.println("Prompt #" + num + " resolved");
            }
        };
    }
}