JavaFX Running a large amount of countdown timers at once?

Question

So I can see a couple different ways to do what I need and I\'ve done a bunch of google/stack overflow searching but can\'t find really what I\'m looking for. I need to run mult

Answer 1

Here is another way, standard java. Depending on how long the countdown runs one may want to stop those executors when the GUI is closed. I am using the ScheduledExecutorService also for multiple countdowns.

import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

public class CountDownExecutor extends Application{

    private final int i= 15;
    private final DateTimeFormatter HH_MM_SS = DateTimeFormatter.ofPattern("HH:mm:ss");
    private final Label l1=new Label("00:00:00");
    private final Insets insets = new Insets(3,5,3,5);
    private final Button button = new Button("Start");

    private ScheduledExecutorService executor=null;
    private AtomicInteger atomicInteger = new AtomicInteger();

    public static void main(String[] args) {
        Application.launch(CountDownExecutor.class, args);
    }

    @Override
    public void start(Stage stage) {
        HBox hb = new HBox();
        button.setOnMouseClicked(a-> countDown());
        button.setPadding(insets);
        l1.setPadding(insets);
        hb.getChildren().addAll(button,l1);
        Scene scene = new Scene(hb);
        stage.setOnCloseRequest((ev)-> {if(executor!=null) executor.shutdownNow();});
        stage.setScene(scene);
        stage.show();
    }

    public void countDown() {
        Platform.runLater( () -> button.setDisable(true));
        atomicInteger.set(i);
        setCountDown(LocalTime.ofSecondOfDay(atomicInteger.get()));
        executor = Executors.newScheduledThreadPool(1);

        Runnable r = ()->{
            int j = atomicInteger.decrementAndGet();
            if(j<1 ){
                executor.shutdown();
                Platform.runLater( () ->{ 
                    button.setDisable(false);
                });
                setCountDown(LocalTime.ofSecondOfDay(0));
            }else {
                setCountDown(LocalTime.ofSecondOfDay(j));
            }
        };
        executor.scheduleAtFixedRate(r, 1, 1, TimeUnit.SECONDS);
    }

    public void setCountDown(LocalTime lt)  { Platform.runLater(() -> l1.setText(lt.format(HH_MM_SS))); }
}