Type Members

1.  trait ActorModule extends AbstractModule

   Allows runtime dependency injection of actor behavior, defined in "functional programming" style.

   Allows runtime dependency injection of actor behavior, defined in "functional programming" style.

   1. Mix this trait into the object defining the actor messages and the actor behavior(s), 2. Define the Message type with actor message class, 3. Add the Provides annotation to the method that returns the (initial) Behavior of the actor. 4. Use the bindTypedActor in AkkaGuiceSupport, passing the object as the actor module.

   For example:

   object ConfiguredActor extends ActorModule {
     type Message = GetConfig
   
     final case class GetConfig(replyTo: ActorRef[String])
   
     @Provides def apply(configuration: Configuration): Behavior[GetConfig] = {
       // TODO: Define ConfiguredActor's behavior using the injected configuration.
       Behaviors.empty
     }
   }
   
   final class AppModule extends AbstractModule with AkkaGuiceSupport {
     override def configure() = {
       bindTypedActor(classOf[ConfiguredActor], "configured-actor")
     }
   }

   Annotations

   @ApiMayChange()

   See also

   https://doc.akka.io/docs/akka/snapshot/typed/style-guide.html#functional-versus-object-oriented-style

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

   Provider for creating actor refs

3.  class ActorSystemProvider extends Provider[ActorSystem]

   Provider for the actor system

   Provider for the actor system

   Annotations

   @Singleton()

4.  trait AkkaComponents extends AnyRef

   Components for configuring Akka.

5.  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")
       bindTypedActor(HelloActor(), "hello-actor")
     }
   }

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

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

6.  class CoordinatedShutdownProvider extends Provider[CoordinatedShutdown]

   Provider for the coordinated shutdown

   Provider for the coordinated shutdown

   Annotations

   @Singleton()

7.  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

   Dispatchers

   Thread Pools

8.  class DefaultFutures extends Futures

   ActorSystem based timeout.

9.  class ExecutionContextProvider extends Provider[ExecutionContextExecutor]

   Provider for the default execution context

   Provider for the default execution context

   Annotations

   @Singleton()

10.  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

11.  trait InjectedActorSupport extends AnyRef

    Support for creating injected child actors.

12.  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
    }

13.  class MaterializerProvider extends Provider[Materializer]

    Provider for the default flow materializer

    Provider for the default flow materializer

    Annotations

    @Singleton()

14.  final class TypedActorRefProvider[T] extends Provider[ActorRef[T]]

    A singleton Provider of the typed ActorRef[T] resulting from spawning an actor with the Behavior[T] in dependency scope and the given name, in the ActorSystem in dependency scope.

    A singleton Provider of the typed ActorRef[T] resulting from spawning an actor with the Behavior[T] in dependency scope and the given name, in the ActorSystem in dependency scope.

    T

    The class of the messages the typed actor can handle.

    Annotations

    @Singleton() @ApiMayChange()