How to stop a running TimerTask

Question

I am trying to make a simple timer that plays a beep after the specified number of seconds. I managed to get it to work, but the TimerTask continues to run after the beep. Now do I stop execution? Here is my code:

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

You need to cancel the timer by calling the following methods

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

This will cancel the task, so something like this would work:

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;
    }
}

Answer 2

Here is what worked for me (used the purge() suggestion also):

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;

        final Timer timer = new Timer();

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

        timer.schedule(task, delay);
    }
}

Answer 3

cancel()应该这样做 - cancel停止取消给定的TimerTask / Timer

Answer 4

isStart = true; // if true timmer function countiue called , else time canceled
Timer timer = new Timer(); timer.schedule(new TimerClass(), 0, 5000);

class TimerClass extends TimerTask {
    
    public void run() {
        
        if (isStart) {
           yourFunction();
        }else {
            cancel();
        }

    }
}