使用 ScheduledExecutorService 仅在特定日期时间运行编码一次

Question

我有一个代码必须在将来的某个日期时间执行，假设我有一个未来的日期并且我想执行一个安静的代码在该日期+1 分钟后，但只有一次。我知道我要用 java Timer 和 TimerTask 来做到这一点。例如做这样的事情：

import java.util.Calendar;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;

public class Main {

    public static void main(String[] args) {

        Calendar myDate = Calendar.getInstance();
        myDate.add(Calendar.MINUTE, 1);
        Date afterOneMinute = myDate.getTime();
        System.out.println("Scheduled at:" + afterOneMinute);
        Timer timer = new Timer();

        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                System.out.println("Executed at:" + (new Date()));

            }
        }, afterOneMinute);
    }

}

我正在寻找一种优雅的方式来使用 ScheduledExecutorService，以便拥有一个特定的池，因为这个池将用于多个调用。有人可以帮助我吗？

Answer 1

您可以使用ScheduledExecutorService.schedule(Runnable command, long delay, TimeUnit unit)

long delay = afterOneMinute.getTime() - System.currentTimeMillis();
ScheduledExecutorService executorService = ...;
executorService.schedule(runnable, delay, TimeUnit.MILLISECONDS);

Answer 2

您可以从 Executors 获得 ScheduledExecutorService，获得 SingleThread 版本或 MultipleThread Executors.newSingleThreadScheduledExecutor
然后提供runnable、duration及其TimeUnit：ScheduledExecutorService.schedule(Runnable command, long delay, TimeUnit unit)

如果要设置持续时间：

ScheduledExecutorService exe = Executors.newSingleThreadScheduledExecutor();
// or Executors.newScheduledThreadPool(2); if you have multiple tasks
exe.schedule(() -> System.out.println("Executed at:" + (new Date())), 1, TimeUnit.MINUTES);

如果你想使用 LocalDateTime :

ScheduledExecutorService exe = Executors.newSingleThreadScheduledExecutor();
// or Executors.newScheduledThreadPool(2); if you have multiple tasks
LocalDateTime date = LocalDateTime.of(2018, 6, 17, 18, 30, 0);
exe.schedule(
       () -> System.out.println("Executed at:" + (new Date())),
       LocalDateTime.now().until(date, ChronoUnit.MINUTES),
       TimeUnit.MINUTES);

使用 ScheduledExecutorService 仅在特定日期时间运行编码一次

Use ScheduledExecutorService to run code at specific Date time only once

java

timertask

scheduledexecutorservice

使用 ScheduledExecutorService 仅在特定日期时间 运行 编码一次

Use ScheduledExecutorService to run code at specific Date time only once

java

timertask

scheduledexecutorservice

使用 ScheduledExecutorService 仅在特定日期时间运行编码一次