如何停止正在运行的TimerTask

Question

我正在尝试制作一个简单的计时器，该计时器在指定的秒数后发出提示音。我设法使其正常工作，但是TimerTask在蜂鸣声后继续运行。现在我停止执行吗？这是我的代码：

import java.util.Scanner;
import java.util.Timer;
import java.util.TimerTask;
import java.awt.Toolkit;

class Alarm {

    public static void main(String[] args) {
        long delay;
        Scanner scan = new Scanner(System.in);
        System.out.print("Enter a delay in seconds: ");
        delay = scan.nextInt()*1000;

        Timer timer = new Timer();

        TimerTask task = new TimerTask() {
            @Override
            public void run() {
                Toolkit.getDefaultToolkit().beep();
            }
        };

        timer.schedule(task, delay);
    }
}

Answer 1

您需要通过调用以下方法来取消计时器

timer.cancel();  // Terminates this timer, discarding any currently scheduled tasks.
timer.purge();   // Removes all cancelled tasks from this timer's task queue.

这将取消任务，因此可以执行以下操作：

import java.util.Scanner;
import java.util.Timer;
import java.util.TimerTask;
import java.awt.Toolkit;

class Alarm {

    private static boolean run = true;

    public static void main(String[] args) {
        long delay;
        Scanner scan = new Scanner(System.in);
        System.out.print("Enter a delay in seconds: ");
        delay = scan.nextInt()*1000;

        final Timer timer = new Timer();

        final TimerTask task = new TimerTask() {
            @Override
            public void run() {
                if(run) {
                   Toolkit.getDefaultToolkit().beep();
                } else {
                   timer.cancel();
                   timer.purge();
                }
            }
        };

        timer.schedule(task, delay);

        // set run to false here to stop the timer.
        run = false;
    }
}