ScheduledThreadPollExecutor

public class Game {
    private int corePoolSize=2;
    private static ScheduledThreadPoolExecutor stpe;
    protected static Hashtable<Integer, Rock> rocksList;
    protected static Hashtable<Integer, Shot> shotsList;
    protected static Enumeration<Rock> enumAst;
    protected static Enumeration<Shot> enumShot;
    protected static Rock tempRock;
    protected static Ship ship;
    protected static Shot shots;

    public void methodeEnCaca() {
        Game.stpe = new ScheduledThreadPoolExecutor(this.corePoolSize);
        Game.stpe.scheduleAtFixedRate(new GameThread(), 1, 20, TimeUnit.MILLISECONDS);
    }
}


public class GameThread extends Game implements Runnable {

    public GameThread(){}

    public void run() {
        detectCollision();

        /*
         * boucle demandant à tous les éléments de la liste de mettre leur vue à jour
         */
        Game.enumAst = Game.rocksList.elements();
        while(enumAst.hasMoreElements()) {
            Game.tempRock=enumAst.nextElement();
            Game.tempRock.updatePosition();
        }

        Game.enumShot = Game.shotsList.elements();
        while(enumShot.hasMoreElements()) {
            Game.shots=enumShot.nextElement();
            Game.shots.updatePosition();
        }

        if(Game.ship!=null) {
            Game.ship.updatePosition();
        }

        refreshView(); //méthode demandant à la vue de faire un repaint()
    }
}