java - Playframework + Akka : how to avoid excuting scheduled tasks executed when shutdown application

Question

我在 Play 应用程序服务器启动时启动调度程序，但一旦应用程序关闭，它就会遇到以下代码部分:

// firstDay something like 1 = monday 
private void startScheduler(final ImageService imageService,
                            final ActorSystem system) {
    startImagesCleanupScheduler(imageService, system);
    Logger.info("Schedulers started");
}

我的问题是，Runnable block 立即开始执行，而不是仅仅取消任务。

澄清代码:

以下方法启动Scheduler:

private void startImagesCleanupScheduler(ImageService imageService, ActorSystem system) {
    system.scheduler().schedule(
            Duration.create(0, TimeUnit.MILLISECONDS), //Initial delay
            Duration.create(1, TimeUnit.DAYS),     //Frequency 1 days
            () -> {
                int rows = imageService.cleanupInactiveImages();
                Logger.info(String.format("%d inactive unused images cleaned from db", rows));

            },
            system.dispatcher()
    );
}

关闭时的日志请注意这里的第一行:

[info] - application - 1 inactive unused images cleaned from db
[info] - application - Shutting down connection pool.
[info] - application - Creating Pool for datasource 'default'
...
[info] - application - Schedulers started
[info] - play.api.Play - Application started (Prod)

您可以看到它执行调度程序，忽略其原始执行时间，然后关闭，然后启动，然后“调度程序启动”。

什么问题，我如何取消调度程序或阻止 Play 在关闭之前运行它？这是 Akka 的错误吗？

我在 OnStartup 中调用 startScheduler，就像以下问题的答案:

java Playframework GlobalSettings deprecation for onStart

编辑: 以下是重现问题的最少代码:

首先创建OnStartup类:

@Singleton
public class OnStartup {

    @Inject
    public OnStartup(final ActorSystem system) {
        startScheduler(system);
    }

    private void startScheduler(final ActorSystem system) {
        startImagesCleanupScheduler(system);
        Logger.info("Schedulers started");
    }

    private void startImagesCleanupScheduler(ActorSystem system) {
        system.scheduler().schedule(
                Duration.create(0, TimeUnit.MILLISECONDS), //Initial delay
                Duration.create(1, TimeUnit.DAYS),     //Frequency 1 days
                () -> {
                    //int rows = imageService.cleanupInactiveImages();
                    rows = 1;
                    Logger.info(String.format("%d inactive unused images cleaned from db", rows ));
                },
                system.dispatcher()
        );
    }

}

然后创建模块:

public class OnStartupModule extends AbstractModule {
    @Override
    public void configure() {
        bind(OnStartup.class).asEagerSingleton();
    }
}

最后在 application.conf 中启用模块:

play.modules.enabled += "modules.OnStartupModule"

Answer 1

这对于评论来说有点太长了，但我没有测试这种方法，您可能需要调整它。文档说组件会按照创建的相反顺序被销毁。这意味着您可能会在 ActorSystem 关闭之前取消调度程序，因为此类在它之后注册并依赖于它。在您的 OnStartup 类中创建一个像这样的关闭 Hook ，您将在其中取消您的计划。这意味着在 ActorSystem 关闭时，将没有要执行的计划:

@Singleton
public class OnStartup {

    private final Cancellable cancellableSchedule;

    @Inject
    public OnStartup(final ActorSystem system, final ApplicationLifecycle l) {
        cancellableSchedule = startScheduler(system);
        initStopHook(l);
    }

    private Cancellable startScheduler(final ActorSystem system) {
        return startImagesCleanupScheduler(system);
        Logger.info("Schedulers started");
    }

    private Cancellable startImagesCleanupScheduler(ActorSystem system) {
        return system.scheduler().schedule(
            Duration.create(0, TimeUnit.MILLISECONDS), //Initial delay
            Duration.create(1, TimeUnit.DAYS),     //Frequency 1 days
            () -> {
                //int rows = imageService.cleanupInactiveImages();
                rows = 1;
                Logger.info(String.format("%d inactive unused images cleaned from db", rows ));
                },
            system.dispatcher()
        );
    }

    private void initStopHook(ApplicationLifecycle lifecycle) {
       lifecycle.addStopHook(() -> {
            cancellableSchedule.cancel();
        return CompletableFuture.completedFuture(null);
        });
     }

}