Java：以随机间隔调度任务 [英] Java: Scheduling a task in random intervals

问题描述

我是Java的新手，我正在尝试生成一个每5到10秒运行一次的任务，所以在5到10之间的任何时间间隔，包括10。

I am quite new to Java and I'm trying to generate a task that will run every 5 to 10 seconds, so at any interval in the area between 5 to 10, including 10.

我尝试了几件事但到目前为止没有任何工作。我最近的努力如下：

I tried several things but nothing is working so far. My latest effort is below:

timer= new Timer();
Random generator = new Random();
int interval;

//The task will run after 10 seconds for the first time:
timer.schedule(task, 10000); 

//Wait for the first execution of the task to finish:               
try {
    sleep(10000);
} catch(InterruptedException ex) {
ex.printStackTrace();
}

//Afterwards, run it every 5 to 10 seconds, until a condition becomes true:
while(!some_condition)){
    interval = (generator.nextInt(6)+5)*1000;
    timer.schedule(task,interval);

    try {
        sleep(interval);
    } catch(InterruptedException ex) {
    ex.printStackTrace();
    }
}

task是一个TimerTask。我得到的是：

"task" is a TimerTask. What I get is:

Exception in thread "Thread-4" java.lang.IllegalStateException: Task already scheduled or cancelled

我理解这里，TimerTask无法重复使用，但我不知道如何修复它。顺便说一下，我的TimerTask非常复杂，至少持续1.5秒。

I understand from here that a TimerTask cannot be reused, but I am not sure how to fix it. By the way the my TimerTask is quite elaborate and lasts itself at least 1,5 seconds.

任何帮助都将非常感谢，谢谢！

Any help will be really appreciated, thanks!

推荐答案

尝试

public class Test1 {
    static Timer timer = new Timer();

    static class Task extends TimerTask {
        @Override
        public void run() {
            int delay = (5 + new Random().nextInt(5)) * 1000;
            timer.schedule(new Task(), delay);
            System.out.println(new Date());
        }

    }

    public static void main(String[] args) throws Exception {
        new Task().run();
    }
}

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