// Thread Variable
private Thread gameThread;

public synchronized void start() {
    if (running) {
        return;
    }
    running = true;
    gameThread = new Thread(this);
    gameThread.start();
}

public synchronized void stop() {
    if (!running) {
        return;
    }
    running = false;
    try {
        gameThread.join();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

// Der eigentliche Game Loop
// Die Klasse implementiert Runnable
public void run() {
    this.requestFocus();
    init();
    long lastTime = System.nanoTime();
    double amountOfTicks = 60.0;
    double ns = 1000000000 / amountOfTicks;
    double delta = 0;
    long timer = System.currentTimeMillis();
    while (running) {
        long now = System.nanoTime();
        delta += (now - lastTime) / ns;
        lastTime = now;
        while (delta >= 1) {
            tick();
            delta--;
        }
        render();
        if (System.currentTimeMillis() - timer > 1000) {
            timer += 1000;
        }
    }
}

// Alles Render Zeugs
private void render() {
}

// Alle Updates
private void tick() {
}

// Main Methode
public static void main(String[] args) {
    new Game().start();
}