Change javafx circles color in certain time using multithreads

Question

I am creating traffic light simulator with javafx that changes colour in every 2 seconds (first red light blinks and remain for 2 seconds) using the concept of multithreading. I

Answer 1

I was so confused on how to make this work honestly I agree with Sedrick check out the JavaFX Animation class but I was bored so I made this work also there is definitely better ways to do this but I did my best to try and keep as much code as possible because you wanted to lean from this. Just looked at this again its p̶r̶e̶t̶t̶y̶ ̶m̶u̶c̶h̶ only the variable names lol

public class Main extends Application {

    private Circle circle;
    private Circle circle1;
    private Circle circle2;
    private HashMap colorHashMap = new HashMap<>();
    private HashMap counterHashMap = new HashMap<>();

    @Override
    public void start(Stage stage) {
        circle = new Circle(15, 15,30, Color.GREEN);
        colorHashMap.put(circle,Color.GREEN);
        counterHashMap.put(circle, 3);//Start On

        circle1 = new Circle(15, 45,30, Color.GREY);
        colorHashMap.put(circle1,Color.YELLOW);
        counterHashMap.put(circle1, 2);

        circle2 = new Circle(15, 60,30, Color.GREY);
        colorHashMap.put(circle2,Color.RED);
        counterHashMap.put(circle2, 1);

        VBox vBox = new VBox();
        vBox.getChildren().addAll(circle,circle1,circle2);

        Scene scene = new Scene(vBox);
        stage = new Stage();
        stage.setScene(scene);
        stage.show();

        try {
            startThreads();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    private void startThreads() throws InterruptedException {
        new Thread(()->{
            while (true) {
                flipColor(circle);
                flipColor(circle1);
                flipColor(circle2);

                try {
                    Thread.sleep(2000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }

    private void flipColor(Circle circle){
        if(counterHashMap.get(circle)%3==0) {
            Platform.runLater(()->circle.setFill(colorHashMap.get(circle)));
            counterHashMap.put(circle,1);
        }
        else {
            if(!circle.getFill().equals(Color.GREY))
                Platform.runLater(()->circle.setFill(Color.GREY));
            counterHashMap.put(circle,counterHashMap.get(circle)+1);
        }

    }

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