ScheduledExecutorService如何知道1个runnables完成

Question

我正在使用ExecutorService，线程池为3或4.我将它们安排为scheduleWithFixedDelay方法。我想做的是当一个任务完成我想每次运行一个新线程 。我的runnables是一个类，并没有在当前类中实现。您可以在下面找到我执行的上述任务。我无法使用CountDownLatch，因为您无法再次实例化它。我怎么知道什么时候完成。

public class StatisticRunnable implements Runnable  {

    private boolean checkWaitingOnCustomer;
    private int start,end;
    private Main main;

    public StatisticRunnable(int start, int end, boolean checkWaitingOnCustomer, Main main) {
        this.start = start;
        this.end = end;
        this.checkWaitingOnCustomer = checkWaitingOnCustomer;
        this.main = main;
    }

    @Override
    public void run() {
        main.runStatisticsInBackground(start,end, checkWaitingOnCustomer);
    }
}

在我的主要班级

 statisticsExecutor = Executors.newScheduledThreadPool(statisticsThreadCount);
            int average = (int) (Math.ceil((usersForStatistics.size()*1d)/(statisticsThreadCount *1d)));
            boolean checkKullanicidaBekliyor = false;
            for(int start = 0;  start < usersForStatistics.size(); start+= average){
                int end =start + average - 1;
                if(end > usersForStatistics.size()-1){
                    end = usersForStatistics.size()- 1;
                    checkKullanicidaBekliyor = true;
                }
                statisticsExecutor.scheduleWithFixedDelay(new StatisticRunnable(start,end,checkKullanicidaBekliyor,this),2,DefaultValues.statisticsRefreshTime,TimeUnit.SECONDS);
            }