How to reset the game ?

Newbie & Debugging Questions
#1

I’m using Graphics2D with java and I want to reset the game if the alien ship hit my ship.
I tried some different things but didn’t worked.

Here’s the JFrame class:


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

public class Window extends JFrame {

    public Window() {
        add(new Screen());
        setTitle("Square Invaders!");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setSize(900, 560);
        setLocationRelativeTo(null);
        setVisible(true);
        setResizable(false);  
    }

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

Here’s the part of the code where I check if the game ended which resides in the
Sceen.java class (extends JPanel):


public void paintComponent(Graphics g) {
        Graphics2D g2d = (Graphics2D) g;
        super.paintComponent(g);
        if (ingame) {
            if (spaceShip.isVisible()) {
                drawSpaceShip(g);
            }
            drawAlienShip(g);

            g2d.setColor(Color.white);
            g2d.drawString("Squares left: " + aliens.size(), 5, 15);
        } else {
            String msg = "Game Over";
            Font small = new Font("Viner Hand ITC", Font.BOLD, 36);
            FontMetrics metr = this.getFontMetrics(small);

            g.setColor(Color.white);
            g.setFont(small);
            g.drawString(msg, (S_WIDTH - metr.stringWidth(msg)) / 2,
                    S_HEIGHT / 2 - metr.getHeight());
        }
        g.dispose();
    }

I tried to do this(by adding the : new Window()):


            g.drawString(msg, (S_WIDTH - metr.stringWidth(msg)) / 2,
                    S_HEIGHT / 2 - metr.getHeight());
            new Window();
        }
        g.dispose();
    }

the result is a window after window is being created !