concurrent

Type Members

1. class ActorRefProvider[T <: Actor] extends Provider[ActorRef]

   

   Provider for creating actor refs

2. class ActorSystemProvider extends Provider[ActorSystem]

   

   Provider for the actor system

   Provider for the actor system

   Annotations

   @Singleton()

3. trait AkkaComponents extends AnyRef

   

   Components for configuring Akka.

4. trait AkkaGuiceSupport extends AnyRef

   

   Support for binding actors with Guice.

   Support for binding actors with Guice.

   Mix this trait in with a Guice AbstractModule to get convenient support for binding actors. For example:

   class MyModule extends AbstractModule with AkkaGuiceSupport {
     def configure = {
       bindActor[MyActor]("myActor")
     }
   }

   Then to use the above actor in your application, add a qualified injected dependency, like so:

   class MyController @Inject() (@Named("myActor") myActor: ActorRef, val controllerComponents: ControllerComponents)
       extends BaseController {
     ...
   }

5. abstract class CustomExecutionContext extends ExecutionContextExecutor

   

   This class defines a custom execution context that delegates to an akka.actor.ActorSystem.

   This class defines a custom execution context that delegates to an akka.actor.ActorSystem.

   It is very useful for situations in which the default execution context should not be used, for example if a database or blocking I/O is being used.

   To define a custom context, subclass CustomExecutionContext with the dispatcher name:

   @Singleton
   class DatabaseExecutionContext @Inject()(system: ActorSystem)
      extends CustomExecutionContext(system, "database-dispatcher")

   and then bind it in dependency injection:

   bind[DatabaseExecutionContext].to(classOf[DatabaseExecutionContext]).asEagerSingleton()

   Then have the execution context passed in as an implicit parameter:

   class DatabaseService @Inject()(implicit executionContext: DatabaseExecutionContext) {
     ...
   }

   See also

   Thread Pools

   Dispatchers

6. class DefaultFutures extends Futures

   

   ActorSystem based timeout.

7. class ExecutionContextProvider extends Provider[ExecutionContextExecutor]

   

   Provider for the default execution context

   Provider for the default execution context

   Annotations

   @Singleton()

8. trait Futures extends AnyRef

   

   This trait is used to provide non-blocking timeouts and delays on an operation that returns a Future.

   This trait is used to provide non-blocking timeouts and delays on an operation that returns a Future.

   You can dependency inject the Futures as follows to create a Future that will timeout after a certain period of time:

   class MyService @Inject()(futures: Futures, piCalculator: PiCalculator) extends Timeout {
     def calculateWithTimeout(timeoutDuration: FiniteDuration): Future[Int] = {
       futures.timeout(timeoutDuration)(piCalculator.rawCalculation())
     }
   }

   And you can also use a delay to return data after a given period of time.

   class PiCalculator @Inject()(futures: Futures) {
     def rawCalculation(): Future[Int] = {
       futures.delay(300 millis) { Future.successful(42) }
     }
   }

   You should check for timeout by using scala.concurrent.Future.recover or scala.concurrent.Future.recoverWith and checking for scala.concurrent.TimeoutException:

   val future = myService.calculateWithTimeout(100 millis).recover {
     case _: TimeoutException =>
       -1
   }

   See also

   Futures and Promises

9. trait InjectedActorSupport extends AnyRef

   

   Support for creating injected child actors.

10. trait LowPriorityFuturesImplicits extends AnyRef

    

    Low priority implicits to add withTimeout methods to scala.concurrent.Future.

    Low priority implicits to add withTimeout methods to scala.concurrent.Future.

    You can dependency inject the ActorSystem as follows to create a Future that will timeout after a certain period of time:

    class MyService @Inject()(piCalculator: PiCalculator)(implicit futures: Futures) {
    
      def calculateWithTimeout(timeoutDuration: FiniteDuration): Future[Int] = {
         piCalculator.rawCalculation().withTimeout(timeoutDuration)
      }
    }

    You should check for timeout by using scala.concurrent.Future.recover or scala.concurrent.Future.recoverWith and checking for scala.concurrent.TimeoutException:

    val future = myService.calculateWithTimeout(100 millis).recover {
      case _: TimeoutException =>
        -1
    }

11. class MaterializerProvider extends Provider[Materializer]

    

    Provider for the default flow materializer

    Provider for the default flow materializer

    Annotations

    @Singleton()

12. trait Timeout extends AnyRef

    

    This trait is used to provide a non-blocking timeout on an operation that returns a Future.

    This trait is used to provide a non-blocking timeout on an operation that returns a Future.

    Please note that the play.api.Application default ActorSystem should be used as input here, as the actorSystem.scheduler is responsible for scheduling the timeout, using akka.pattern.actor under the hood.

    You can dependency inject the ActorSystem as follows to create a Future that will timeout after a certain period of time:

    class MyService(val actorSystem: ActorSystem) extends Timeout {
    
      def calculateWithTimeout(timeoutDuration: FiniteDuration): Future[Int] = {
        timeout(actorSystem, timeoutDuration)(rawCalculation())
      }
    
      def rawCalculation(): Future[Int] = {
        import akka.pattern.after
        implicit val ec = actorSystem.dispatcher
        akka.pattern.after(300 millis, actorSystem.scheduler)(Future(42))(actorSystem.dispatcher)
      }
    }

    You should check for timeout by using Future.recover() or Future.recoverWith() and checking for TimeoutException:

    val future = myService.calculateWithTimeout(100 millis).recover {
      case _: TimeoutException =>
        -1
    }

    Annotations

    @deprecated

    Deprecated

    (Since version 2.6.0) Use play.api.libs.concurrent.Futures.timeout

    See also

    Futures and Promises