在另一个Task Java中安排任务

Question

我开发了一个程序，该程序每两分钟调用一次db以检查新任务

public static void main(String[] args) {
ScheduledExecutorService scheduler =     Executors.newSingleThreadScheduledExecutor();
scheduler.scheduleWithFixedDelay(new ESMSCampaignTask(), 0, 2, TimeUnit.MINUTES);
}

现在下面的代码从数据库检查并执行线程

public void run() {

    ExecutorService execService = Executors.newFixedThreadPool(5);

    List<ScheduledCampaigns> scheduledCampaignsList =   campaignsService.getScheduledCampaigns();

    for (ScheduledCampaigns campaign : scheduledCampaignsList) {

        String cmpName = "SCH_CAMPAIGNS_" + campaign.getCampaign_id();

        execService.execute(new Runnable() {
            public void run() {
                smppService.submitShortMessage(campaign);
            }
        });

    }//EO For Loop

}//EO Run

我正在寻找的解决方案是如何获取上述线程的完成状态，以便相应地更新数据库？

我试图execService.awaitTermination（500，TimeUnit.SECONDS）;

但是，在现有线程完成其任务之前，我将无法启动新线程。

因此，解决方案应提供这样的功能，即每隔两分钟我就可以启动新线程，而无需等待现有线程完成，同时我不断获取线程完成状态，因此可以相应地更新数据库。

问候，

Answer 1

如果使用ExcecutorService.submit()而不是execute ，则可以获取Future对象。 将其存储在向量中，然后可以遍历此向量中的项目以检查其完成状态。

/**  keep track of currently running tasks */
Vector runningTasks<Future> = new Vector<Future>();

public void run(){
  for (ScheduledCampaigns campaign : scheduledCampaignsList) {

    String cmpName = "SCH_CAMPAIGNS_" + campaign.getCampaign_id();

    Future f = execService.submit(new Runnable() {
        public void run() {
            smppService.submitShortMessage(campaign);
        }
    });
    runningTasks.add(f);

  }//EO For Loop

  // which tasks have just completed?
  Vector<Future> justCompletedTasks = new Vector<Future>();

  // check currently executing tasks
  for (Future task : runningTasks){
   if( task.isDone() || tasks.isCancelled() ){
      justCompletedTasks.add(task);
   }
  } // EO check executing tasks

  // remove completed tasks from current list
  runningTasks.removeAll(justCompletedTasks);
} // EO run

抱歉，这是未经测试的，但是希望这个想法有用吗？