Timer 和 TimerTask - 如何从 TimerTask 运行中重新安排 Timer [英] Timer and TimerTask - how to reschedule Timer from within TimerTask run

问题描述

基本上我想做的是制作一个在 x 秒后运行特定 TimerTask 的 Timer，但是 TimerTask 可以重新安排 Timer 在 y 秒后执行任务.示例如下，它给我一个错误线程Timer-0"中的异常java.lang.IllegalStateException:任务已经安排或取消"在线我尝试在TimerTask运行中安排此任务.

basically what I want to do is to make a Timer that runs a specific TimerTask after x seconds, but then the TimerTask can reschedule the Timer to do the task after y seconds. Example is below, it gives me an error "Exception in thread "Timer-0" java.lang.IllegalStateException: Task already scheduled or cancelled" on line where I try to schedule this task in TimerTask run.

import java.util.Timer;
import java.util.TimerTask;

public class JavaReminder {

    public JavaReminder(int seconds) {
        Timer timer = new Timer();  
        timer.schedule(new RemindTask(timer, seconds), seconds*2000);
    }

    class RemindTask extends TimerTask {
        Timer timer;
        int seconds;
        RemindTask(Timer currentTimer, int sec){
            timer = currentTimer;
            seconds = sec;
        }

        @Override
        public void run() {
            System.out.println("ReminderTask is completed by Java timer");
            timer = new Timer(); 
            timer.schedule(this, seconds*200);
            System.out.println("scheduled");
        }
    }

    public static void main(String args[]) {
        System.out.println("Java timer is about to start");
        JavaReminder reminderBeep = new JavaReminder(2);
        System.out.println("Remindertask is scheduled with Java timer.");
    }
}

推荐答案

使用新的 RemindTask 而不是现有的.

Use new RemindTask instead of existing one.

应该是

timer.schedule(new RemindTask(timer, seconds), seconds*200);

代替

timer.schedule(this, seconds*200);

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