java - 是否有检查计时器是否正在运行的代码？

Question

我有一个游戏，我在其中安排计时器。我有这个 CoresManager 文件:

package com.rs.cores;

 import java.util.Timer;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;

 public final class CoresManager {

protected static volatile boolean shutdown;
public static WorldThread worldThread;
public static ExecutorService serverWorkerChannelExecutor;
public static ExecutorService serverBossChannelExecutor;
public static Timer fastExecutor;
public static ScheduledExecutorService slowExecutor;
public static int serverWorkersCount;

public static void init() {
    worldThread = new WorldThread();
    int availableProcessors = Runtime.getRuntime().availableProcessors();
    serverWorkersCount = availableProcessors >= 6 ? availableProcessors - (availableProcessors >= 12 ? 7 : 5) : 1;
    serverWorkerChannelExecutor = availableProcessors >= 6 ? Executors
            .newFixedThreadPool(availableProcessors - (availableProcessors >= 12 ? 7 : 5),
            new DecoderThreadFactory()) : Executors.newSingleThreadExecutor(new DecoderThreadFactory());
    serverBossChannelExecutor = Executors
            .newSingleThreadExecutor(new DecoderThreadFactory());
    fastExecutor = new Timer("Fast Executor");
    slowExecutor = availableProcessors >= 6 ? Executors.newScheduledThreadPool(availableProcessors >= 12 ? 4 : 2,
                    new SlowThreadFactory()) : Executors
            .newSingleThreadScheduledExecutor(new SlowThreadFactory());
    worldThread.start();
}

public static void shutdown() {
    serverWorkerChannelExecutor.shutdown();
    serverBossChannelExecutor.shutdown();
    fastExecutor.cancel();
    slowExecutor.shutdown();
    shutdown = true;
}

private CoresManager() {

}
}

我在游戏中使用这个:

    private void startTimer() {
    CoresManager.fastExecutor.scheduleAtFixedRate(new TimerTask() {
        @Override
        public void run() {
            if (timer == 0 || timer < 1) {
                player.sm("Your timer has ended! The NPCs will no longer spawn.");
                timer = 0;
                this.cancel();
                exitInstance(); 
                return;
            }
            timer--;
            timerchecker = true;
            seconds = timer % 60;
            player.setTimer(timer);
            minutes = TimeUnit.SECONDS.toMinutes(timer);            
        }
    }, 0, 1000);
}

如果玩家注销并且服务器重新启动，则 CoresManager 计时器将停止运行。为了使其再次运行，我添加了一段代码，使其在您重新登录后再次执行 startTimer()。但是，由于如果服务器未注销，计时器仍在运行，因此计时器开始运行两次。计时器开始减去 2 或更多，具体取决于您注销和登录的次数。我认为如果有代码来确定计时器是否已经运行，它会修复。有没有办法做到这一点？请帮忙!

Answer 1

我在提供检查 TimerTask 对象 (http://docs.oracle.com/javase/1.5.0/docs/api/java/util/TimerTask.html) 状态的文档中没有看到任何内容，因此一种选择是扩展 TimerTask 并创建您自己的类。除了使用匿名 TimerTask，您还可以按照以下方式创建一些内容:

public class CoresTimerTask extends TimerTask {

    private boolean hasStarted = false;

    @Overrides
    public void run() {
        this.hasStarted = true;
        //rest of run logic here...
    }

    public boolean hasRunStarted() {
        return this.hasStarted;
    }
}

并仅维护对此 CoresTimerTask 对象的引用，然后将其传递给 startTimer()。然后您可以稍后通过 hasRunStarted 检查此对象。