import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
public class Main {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton button = new JButton("Button");
frame.add(button);
frame.setAlwaysOnTop(true);
frame.setSize(500, 500);
frame.setLocation(500, 500);
button.addActionListener(e->{
JOptionPane optionPane = new JOptionPane("Option Pane");
optionPane.showMessageDialog(frame, "Message!");
});
frame.setVisible(true);
}
}