Question

我想构建一个计划程序，该程序将定期运行多个任务。这是我的SchedulerExecutor单例，它执行2个操作，开始和停止。 SchedulerProperty拥有一些基本属性，例如初始延迟，连续延迟，超时秒数等。

public class SchedulerExecutor {
private static SchedulerExecutor ourInstance = new SchedulerExecutor();
public static SchedulerExecutor getInstance() {
    return ourInstance;
}

private ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();

private final TaskManager taskManager = new TaskManager();
private final SchedulerService schedulerService = new SchedulerService();


private SchedulerExecutor() { }
public void startScheduler() throws Exception {
    SchedulerProperty property = schedulerService.getCurrentSchedulerProperty();
    if(property.isRunning()){
        throw new RequestFailureException("Scheduler is Already Running");
    }
    property.setRunning(true);
    property.setLastRunningTime(Instant.now().toEpochMilli());
    schedulerService.updateSchedulerProperty(property);
    log.info("Scheduler is Running");
    executorService.scheduleAtFixedRate(taskManager::runPendingTask, property.getInitialDelay(), property.getSuccessiveDelay(), TimeUnit.SECONDS);

}

public void stopScheduler() throws Exception {
    SchedulerProperty property = schedulerService.getCurrentSchedulerProperty();
    if(!property.isRunning()) {
        throw new RequestFailureException("Scheduler is Already Terminated");
    }

    executorService.shutdown();
    try {
        if(!executorService.awaitTermination(property.getTimeoutForTermination(), TimeUnit.SECONDS)){
            executorService.shutdownNow();
        }
    } catch (InterruptedException e) {
        log.fatal(e.getMessage());
        executorService.shutdownNow();
    }

    property.setRunning(false);
    schedulerService.updateSchedulerProperty(property);
    log.info("Scheduler has terminated");
}

}

计划程序将定期运行Taskmanager类的暂挂任务方法。这是我的Taskmanager类

public class TaskManager {
    private final static AtomicInteger atomicInteger = new AtomicInteger(1);
    public void runPendingTask()  {
        log.info(atomicInteger.getAndIncrement() + " Running Pending Task");
        ExecutorService executorService = Executors.newScheduledThreadPool(5);
        TaskService taskService = new TaskService();
        List<Task> pendingTasks = taskService.getPendingTasks();
        pendingTasks.forEach(t->
            executorService.execute(()->{
                log.info("Pending Task: " + t.getTaskName()); 
            }, )
        );
    }
}

问题是，此代码在我第一次启动调度程序时运行良好。它定期在日志中打印消息。但是每当我停止调度程序然后重新启动它时，它就会出现以下异常

Task java.util.concurrent.SchedulerThreadPoolExecutor$ScheduledFutureTask
@318af76f rejected from 
java.util.concurrent.ScheduledThreadPoolExecutor
@2b0847be[Terminated, pool size=0, active threads=0, queued task=0, completed tasks=1]

这是什么解决方案？我还应该移动

ExecutorService executorService = Executors.newScheduledThreadPool(5);

在TaskManager类内部而不是runPendingTask方法？关于此的内存问题/并发问题是什么？

重新启动计划程序后，从计划的线程池执行程序拒绝任务

0 个答案: