如何在Play 2.0.4中每天安排任务+ onStart（）？

Question

我需要每天在playframework2.0.4中执行一段代码，当我尝试使用类扩展GlobalSettings时它可以工作。但它适用于每个请求的实例。我希望它在服务器启动时起作用并且每天执行一次任务。

package controllers;
import java.util.concurrent.TimeUnit;
import akka.util.Duration;
import play.Application;
import play.GlobalSettings;
import play.libs.Akka;

public class ParserJobApp extends GlobalSettings{
@Override
public void onStart(Application app) {
    Akka.system().scheduler().schedule(Duration.create(0, TimeUnit.MILLISECONDS),Duration.create(6, TimeUnit.SECONDS), new Runnable() { 
        @Override
        public void run() {
            System.out.println("AAA ---    "+System.currentTimeMillis());
        }
    });
}
}

这是我的控制器开始上面的课程

public class Application extends Controller {

public static Result index() { 
  ParserJobApp pr=new ParserJobApp();
  pr.onStart(null);
  System.out.println("sfsdfsdf");
return ok(index.render("Your new "));

}
}

Answer 1

调度程序任务应仅放在Global类中。创建两个任务，首先使用initialDelay = 0毫秒计划一次。

对于第二个任务，您需要使用常用日期/时间类计算当前DateTime和下一个计划发生之间的秒数（即明天8:00），然后将此差异设置为initialDelay并将frequency设置为24小时。

结果，它将在应用程序启动时开始，并将在每个所需的时间安排执行任务。

编辑

有完整的样本，（保存/编辑类：/app/Global.java）：

import akka.util.Duration;
import org.joda.time.DateTime;
import org.joda.time.Seconds;
import play.Application;
import play.GlobalSettings;
import play.Logger;
import play.libs.Akka;
import java.util.concurrent.TimeUnit;

public class Global extends GlobalSettings {

    @Override
    public void onStart(Application application) {


        Akka.system().scheduler().scheduleOnce(
                Duration.create(0, TimeUnit.MILLISECONDS),
                new Runnable() {
                    @Override
                    public void run() {
                        Logger.info("ON START ---    " + System.currentTimeMillis());
                    }
                }
        );

        Akka.system().scheduler().schedule(
                Duration.create(nextExecutionInSeconds(8, 0), TimeUnit.SECONDS),
                Duration.create(24, TimeUnit.HOURS),
                new Runnable() {
                    @Override
                    public void run() {
                        Logger.info("EVERY DAY AT 8:00 ---    " + System.currentTimeMillis());
                    }
                }
        );
    }

    public static int nextExecutionInSeconds(int hour, int minute){
        return Seconds.secondsBetween(
                new DateTime(),
                nextExecution(hour, minute)
        ).getSeconds();
    }

    public static DateTime nextExecution(int hour, int minute){
        DateTime next = new DateTime()
                .withHourOfDay(hour)
                .withMinuteOfHour(minute)
                .withSecondOfMinute(0)
                .withMillisOfSecond(0);

        return (next.isBeforeNow())
                ? next.plusHours(24)
                : next;
    }
}

Answer 2

这是我的解决方案，它更轻，支持用于调度的cron表达式。在此示例中，调度程序将在每天上午10:00运行。

关注您的Global课程：

private Cancellable scheduler;

@Override
public void onStart(Application application) {
    super.onStart(application); 
    schedule(); 
}

@Override
public void onStop(Application application) {
    //Stop the scheduler
    if (scheduler != null) {
        scheduler.cancel();
    }
}

private void schedule() {
    try {
        CronExpression e = new CronExpression("0 00 10 ? * *");
        Date nextValidTimeAfter = e.getNextValidTimeAfter(new Date());
        FiniteDuration d = Duration.create(
            nextValidTimeAfter.getTime() - System.currentTimeMillis(), 
            TimeUnit.MILLISECONDS);

        Logger.debug("Scheduling to run at "+nextValidTimeAfter);

        scheduler = Akka.system().scheduler().scheduleOnce(d, new Runnable() {

        @Override
        public void run() {
            Logger.debug("Ruuning scheduler");
            //Do your tasks here

            schedule(); //Schedule for next time

        }
        }, Akka.system().dispatcher());
    } catch (Exception e) {
        Logger.error("", e);
    }
}

Answer 3

这可以使用Global Class完成，并且可以使用onstart方法。 https://www.playframework.com/documentation/2.5.x/JavaGlobal

下面的代码以10分钟间隔打印JVM统计数据。可以配置持续时间以满足需要。

下面给出编码的抽象视图。希望这有帮助

public class Global extends GlobalSettings {

private Cancellable scheduler;

@Override
public void onStart(Application application) {
    int timeDelayFromAppStartToLogFirstLogInMs = 0;
    int timeGapBetweenMemoryLogsInMinutes = 10;
    scheduler = Akka.system().scheduler().schedule(Duration.create(timeDelayFromAppStartToLogFirstLogInMs, TimeUnit.MILLISECONDS),
            Duration.create(timeGapBetweenMemoryLogsInMinutes, TimeUnit.MINUTES),
            new Runnable() {
                @Override
                public void run() {
                    System.out.println("Cron Job");
                    // Call a function (to print JVM stats)
                }
            },
            Akka.system().dispatcher());
    super.onStart(application);
}

@Override
public void onStop(Application app) {
    scheduler.cancel();
    super.onStop(app);
}

}