How to get method to run after timer ends?

Question

(V1) I have a countdown object that deals with displaying a countdown on the JFrame by using a timer. Once the countdown goes to 0, I want the timer to stop and the game to start. However, I realized that even when my countdown isn't finished, my startGame() method is being run, and I cannot find a solution to make it so that the startGame() method only runs after the timer is stopped. So, my question is: is there anyway to make sure the startGame() only runs AFTER the countdown hits zero?

(V2) I tried using countdown.getTimer.isRunning()in the init() method to check whether or not the timer is running (if not then call startGame()) but that didn't seem to work. I'm guessing this is because at the time the if block is called, the timer is still running, so that's why startGame() isn't called... Is this why?

A little explanation of the code: the startCountdown() method tries to display the next image while hiding the last, so I have the catch for the first case where it tries to hide a non-existant image at an index that is out of bounds. Each time the timer ticks, I decrement sec by 1 until it is 0, and then the timer stops.

V1

public void init() {
    countdown.startCountdown();
    countdown.getTimer().start();
    startGame();
}

public void startCountdown() {
    timer = new Timer(1000, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            try {
                if (sec == 0) {
                    countdownIcons.get(0).setVisible(false);
                    timer.stop();
                }
                countdownIcons.get(sec - 1).setVisible(true);
                countdownIcons.get(sec).setVisible(false);
            } catch (IndexOutOfBoundsException exception) {
                if (sec == 0) {
                    timer.stop();
                }
            }
            sec--;
            System.out.println(sec);
        }
    });
}

V2

public void init() {
    countdown.startCountdown();
    countdown.getTimer().start();
    if (!countdown.getTimer().isRunning()) {
        startGame();
    }
}

Answer 1

The problem is that the Timer method runs on a separate thread, different from your main thread.

The way I see it there are two possible solutions:

• call your startGame() method inside startCountdown(), not inside init();
• the second solution would be to pause your main thread and wait for startCountdown() to finish, something like this should work:

public void init() {
    countdown.startCountdown();
    countdown.getTimer().start();
    // pause main thread until timer is notified
    synchronized(timer){
        timer.wait()
        startGame();
    }
}

public void startCountdown() {
    timer = new Timer(1000, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            try {
                if (sec == 0) {
                    countdownIcons.get(0).setVisible(false);
                    timer.stop();
                    // notify your current thread that it can resume execution
                    synchronized(timer){
                         timer.notify();
                    }
                }
                countdownIcons.get(sec - 1).setVisible(true);
                countdownIcons.get(sec).setVisible(false);
            // try not to catch this runtime exception and fix what causes IndexOutOfBoundsException 
            } catch (IndexOutOfBoundsException exception) {
                if (sec == 0) {
                    timer.stop();
                }
            }
            sec--;
            System.out.println(sec);
        }
    });
}