Creating a JDialog in Java Swings

package jdialog;

import javax.swing.*;

public class SimpleJDialogExample {
	
    private static void createAndShowGUI() {     
        // Create a simple JDialog
        JDialog dialog = new JDialog();
        dialog.setTitle("Simple Dialog");
        dialog.setSize(200, 150);
        dialog.setVisible(true);
    }

    public static void main(String[] args) {
        createAndShowGUI();
    }
}

package jdialog;

import javax.swing.*;

public class JDialogOnFrame {
	private static void createAndShowGUI() {
		JFrame frame = new JFrame("Simple JDialog Example");
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setSize(400, 300);
		frame.setVisible(true);

		// Create a simple JDialog
		JDialog dialog = new JDialog(frame, "Simple Dialog", true);
		dialog.setSize(200, 150);
		// Center the dialog relative to the frame
		dialog.setLocationRelativeTo(frame); 

		dialog.setVisible(true);
	}

	public static void main(String[] args) {
		createAndShowGUI();
	}
}