play framework scheduler with Akka at server launch

Question

Question 1: I have created a sample java application using play 2.1.1 with a scheduler to be kicked off when the application is started. I did a play compile and then play start, but i'm getting the below error, please let me know if i'm doing anything wrong here:

(Starting server. Type Ctrl+D to exit logs, the server will remain in background)

Play server process ID is 6160
@6edl861on: Cannot init the Global objectOops, cannot start the server.

    at play.api.WithDefaultGlobal$$anonfun$play$api$WithDefaultGlobal$$globalInstance$1.apply(Application.scala:57)
    at play.api.WithDefaultGlobal$$anonfun$play$api$WithDefaultGlobal$$globalInstance$1.apply(Application.scala:51)
    at play.utils.Threads$.withContextClassLoader(Threads.scala:18)
    at play.api.WithDefaultGlobal$class.play$api$WithDefaultGlobal$$globalInstance(Application.scala:50)
    at play.api.DefaultApplication.play$api$WithDefaultGlobal$$globalInstance$lzycompute(Application.scala:383)
    at play.api.DefaultApplication.play$api$WithDefaultGlobal$$globalInstance(Application.scala:383)
    at play.api.WithDefaultGlobal$class.global(Application.scala:66)
    at play.api.DefaultApplication.global(Application.scala:383)
    at play.api.WithDefaultConfiguration$class.play$api$WithDefaultConfiguration$$fullConfiguration(Application.scala:80)
    at play.api.DefaultApplication.play$api$WithDefaultConfiguration$$fullConfiguration$lzycompute(Application.scala:383)
    at play.api.DefaultApplication.play$api$WithDefaultConfiguration$$fullConfiguration(Application.scala:383)
    at play.api.WithDefaultConfiguration$class.configuration(Application.scala:82)
    at play.api.DefaultApplication.configuration(Application.scala:383)
    at play.api.Application$class.$init$(Application.scala:268)
    at play.api.DefaultApplication.<init>(Application.scala:383)
    at play.core.StaticApplication.<init>(ApplicationProvider.scala:52)
    at play.core.server.NettyServer$.createServer(NettyServer.scala:228)
    at play.core.server.NettyServer$$anonfun$main$5.apply(NettyServer.scala:259)
    at play.core.server.NettyServer$$anonfun$main$5.apply(NettyServer.scala:258)
    at scala.Option.map(Option.scala:145)
    at play.core.server.NettyServer$.main(NettyServer.scala:258)
    at play.core.server.NettyServer.main(NettyServer.scala)
Caused by: java.lang.RuntimeException: There is no started application
    at scala.sys.package$.error(package.scala:27)
    at play.api.Play$$anonfun$current$1.apply(Play.scala:46)
    at play.api.Play$$anonfun$current$1.apply(Play.scala:46)
    at scala.Option.getOrElse(Option.scala:120)
    at play.api.Play$.current(Play.scala:46)
    at play.api.Play.current(Play.scala)
    at play.libs.Akka.system(Akka.java:25)
    at Global.<init>(Global.java:27)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at java.lang.Class.newInstance0(Unknown Source)
    at java.lang.Class.newInstance(Unknown Source)
    at play.api.WithDefaultGlobal$class.play$api$WithDefaultGlobal$$javaGlobal(Application.scala:30)
    at play.api.DefaultApplication.play$api$WithDefaultGlobal$$javaGlobal$lzycompute(Application.scala:383)
    at play.api.DefaultApplication.play$api$WithDefaultGlobal$$javaGlobal(Application.scala:383)
    at play.api.WithDefaultGlobal$$anonfun$play$api$WithDefaultGlobal$$globalInstance$1.apply(Application.scala:52)

Resources:

Global.java - in apps/

public class Global extends GlobalSettings {

private Logger.ALogger log = Logger.of(Global.class);

private ActorRef myActor = Akka.system().actorOf(
        new Props(Retreiver.class));

@Override
public void onStart(Application app) {
    log.info(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
    Akka.system()
            .scheduler()
            .schedule(Duration.create(0, TimeUnit.MILLISECONDS),
                    Duration.create(10, TimeUnit.SECONDS), myActor, "tick",
                    Akka.system().dispatcher());

}
}

Retreiver.java:

public class Retreiver extends UntypedActor {

private Logger.ALogger log = Logger.of(TweetsRetreiver.class);

@Override
public void onReceive(Object arg0) throws Exception {

    // some code here    

}

}

application.conf:

application.global=Global

Question 2: Also, No logs are getting printed either in the console or Application.log file. I have used play.Logger package to do the logging, is this the correct package to be used to log in play 2.1.1? Please provide an example for this.

Thanks.

Answer 1

Solved. Problem with the line:

private ActorRef myActor = Akka.system().actorOf(
    new Props(Retreiver.class));

When i moved this inside the onStart method, it got triggered correctly. Don't know why i can't define this in class level. Need to check.

Answer 2

For the logging question, you have to use the Play's Logger helper :

@Override
public void onStart(Application app) {
    play.Logger.info(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>");
    ...
}