Eclipse: Console is running however no window is appearing

Question

I am following a youtube guide and there are no errors in the code however, when I run the program in the console I have 'running' (I put running loop forever to make sure that the game is working) however no window is popping up for the display. Here is the code

    import java.awt.Canvas;
    import java.awt.Dimension;

    import javax.swing.JFrame;

   public class Game extends Canvas implements Runnable {

private static final long serialVersionUID = 1L;
public static int width = 300;
public static int height = width / 16 * 9;
public static int scale = 3;

private Thread thread;
private JFrame frame;
private boolean running = false;

public Game(){
    Dimension size = new Dimension(width * scale, height * scale);
    setPreferredSize(size);

    frame = new JFrame();
}

public synchronized void start() {
} {
    running = true;
    thread = new Thread(this, "Display");
    thread.start();
}
public synchronized void stop () {
    running = false;
    try {
        thread.join();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}
public void run(){
    while(running){
        System.out.println("running");
    }
}
public static void main(String[] args){
    Game game = new Game();
    game.frame.setResizable(false);
    game.frame.setTitle("Go Home");
    game.frame.add(game);
    game.frame.pack();
    game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    game.frame.setLocationRelativeTo(null);
    game.setVisible(true);

    game.start();
}
}

Answer 1

Okay, so here's a lesson, don't create an instance of JFrame inside your component classes (unless you component class is actually going to use it)

game.setVisible(true); is only setting the visibility state of the Canvas, not the frame

Instead, make the JFrame inside your main method instead

import java.awt.Canvas;
import java.awt.Dimension;
import javax.swing.JFrame;

public class Game extends Canvas implements Runnable {

    private static final long serialVersionUID = 1L;
    public static int width = 300;
    public static int height = width / 16 * 9;
    public static int scale = 3;

    private Thread thread;
    private boolean running = false;

    public Game() {
        Dimension size = new Dimension(width * scale, height * scale);
        setPreferredSize(size);
    }

    public synchronized void start() {
        running = true;
        thread = new Thread(this, "Display");
        thread.start();
    }

    public synchronized void stop() {
        running = false;
        try {
            thread.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public void run() {
        while (running) {
            System.out.println("running");
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame("Go Home");
                Game game = new Game();
                frame.setTitle("Go Home");
                frame.add(game);
                frame.pack();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLocationRelativeTo(null);

                game.start();
            }
        });
    }
}

Also, your start method is actually empty...

public synchronized void start() { } /* What's this? */ { running = true; thread = new Thread(this, "Display"); thread.start(); }

and the thread is actually been started through the static initialisation of the class, not the method call

Answer 2

The JFrame is the main window that will contain components. It must be set visible. On your JFrame object:

frame.setVisible(true);