Was asynchronous jobs removed from the Play framework? What is a better alternative?

问题

I wanted to use Job so I can kick them off on the start of application. Now it seems like it has been removed from Play completely?

I saw some samples where people create a Global class, but not entirely sure if/how I should use that to replace Job.

Any suggestions?

Edit: If you gonna downvote, give a reason. Maybe I'm missing something in the question, maybe this doesn't belong here. At least something...

回答1:

The Job class was removed in Play 2.0.

You have some alternatives though depending on your Play version and if you need asynchrony or not:

Akka Actors

For all version since Play 2.0 you can use Akka Actors to schedule an asynchronous task/actor once and execute it on startup via Play Global class.

public class Global extends GlobalSettings {

    @Override
    public void onStart(Application app) {
           Akka.system().scheduler().scheduleOnce(
               Duration.create(10, TimeUnit.MILLISECONDS),
               new Runnable() {
                    public void run() {
                        // Do startup stuff here
                        initializationTask();
                    }
               },
               Akka.system().dispatcher()
           );
      }  
 }

See https://www.playframework.com/documentation/2.3.x/JavaAkka for details.

Eager Singletons

Starting with Play 2.4 you can eagerly bind singletons with Guice

import com.google.inject.AbstractModule;
import com.google.inject.name.Names;

public class StartupConfigurationModule extends AbstractModule {
    protected void configure() {

        bind(StartupConfiguration.class)
            .to(StartupConfigurationImpl.class)
            .asEagerSingleton();
    }
}

The StartupConfigurationImpl would have it's work done in the default constructor.

@Singleton
public class StartupConfigurationImpl implements StartupConfiguration {
    @Inject
    private Logger log;

    public StartupConfigurationImpl() {
        init();
    }

    public void init(){
        log.info("init");
    }
}

See https://www.playframework.com/documentation/2.4.x/JavaDependencyInjection#Eager-bindings

来源：https://stackoverflow.com/questions/31007478/was-asynchronous-jobs-removed-from-the-play-framework-what-is-a-better-alternat