trait Actor extends AnyRef
Actor base trait that should be extended by or mixed to create an Actor with the semantics of the 'Actor Model': https://en.wikipedia.org/wiki/Actor_model
An actor has a well-defined (non-cyclic) life-cycle.
- RUNNING (created and started actor) - can receive messages
- SHUTDOWN (when 'stop' is invoked) - can't do anything
The Actor's own pekko.actor.ActorRef is available as self
, the current
message’s sender as sender()
and the pekko.actor.ActorContext as
context
. The only abstract method is receive
which shall return the
initial behavior of the actor as a partial function (behavior can be changed
using context.become
and context.unbecome
).
This is the Scala API (hence the Scala code below), for the Java API see pekko.actor.AbstractActor.
class ExampleActor extends Actor { override val supervisorStrategy = OneForOneStrategy(maxNrOfRetries = 10, withinTimeRange = 1 minute) { case _: ArithmeticException => Resume case _: NullPointerException => Restart case _: IllegalArgumentException => Stop case _: Exception => Escalate } def receive = { // directly calculated reply case Request(r) => sender() ! calculate(r) // just to demonstrate how to stop yourself case Shutdown => context.stop(self) // error kernel with child replying directly to 'sender()' case Dangerous(r) => context.actorOf(Props[ReplyToOriginWorker]).tell(PerformWork(r), sender()) // error kernel with reply going through us case OtherJob(r) => context.actorOf(Props[ReplyToMeWorker]) ! JobRequest(r, sender()) case JobReply(result, orig_s) => orig_s ! result } }
The last line demonstrates the essence of the error kernel design: spawn
one-off actors which terminate after doing their job, pass on sender()
to
allow direct reply if that is what makes sense, or round-trip the sender
as shown with the fictitious JobRequest/JobReply message pair.
If you don’t like writing context
you can always import context._
to get
direct access to actorOf
, stop
etc. This is not default in order to keep
the name-space clean.
- Source
- Actor.scala
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- Actor
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- Public
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Type Members
- type Receive = PartialFunction[Any, Unit]
Abstract Value Members
- abstract def receive: Actor.Receive
Scala API: This defines the initial actor behavior, it must return a partial function with the actor logic.
Concrete Value Members
- final def !=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- final def ##: Int
- Definition Classes
- AnyRef → Any
- def +(other: String): String
- def ->[B](y: B): (Actor, B)
- final def ==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- def aroundPostRestart(reason: Throwable): Unit
INTERNAL API.
INTERNAL API.
Can be overridden to intercept calls to
postRestart
. CallspostRestart
by default.- Attributes
- protected[pekko]
- Annotations
- @InternalApi()
- def aroundPostStop(): Unit
INTERNAL API.
INTERNAL API.
Can be overridden to intercept calls to
postStop
. CallspostStop
by default.- Attributes
- protected[pekko]
- Annotations
- @InternalApi()
- def aroundPreRestart(reason: Throwable, message: Option[Any]): Unit
INTERNAL API.
INTERNAL API.
Can be overridden to intercept calls to
preRestart
. CallspreRestart
by default.- Attributes
- protected[pekko]
- Annotations
- @InternalApi()
- def aroundPreStart(): Unit
INTERNAL API.
INTERNAL API.
Can be overridden to intercept calls to
preStart
. CallspreStart
by default.- Attributes
- protected[pekko]
- Annotations
- @InternalApi()
- def aroundReceive(receive: Actor.Receive, msg: Any): Unit
INTERNAL API.
INTERNAL API.
Can be overridden to intercept calls to this actor's current behavior.
- receive
current behavior.
- msg
current message.
- Attributes
- protected[pekko]
- Annotations
- @InternalApi()
- final def asInstanceOf[T0]: T0
- Definition Classes
- Any
- def clone(): AnyRef
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.CloneNotSupportedException]) @HotSpotIntrinsicCandidate() @native()
- implicit val context: ActorContext
Scala API: Stores the context for this actor, including self, and sender.
Scala API: Stores the context for this actor, including self, and sender. It is implicit to support operations such as
forward
.WARNING: Only valid within the Actor itself, so do not close over it and publish it to other threads!
pekko.actor.ActorContext is the Scala API.
getContext
returns a pekko.actor.AbstractActor.ActorContext, which is the Java API of the actor context. - def ensuring(cond: (Actor) => Boolean, msg: => Any): Actor
- def ensuring(cond: (Actor) => Boolean): Actor
- def ensuring(cond: Boolean, msg: => Any): Actor
- def ensuring(cond: Boolean): Actor
- final def eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- def equals(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef → Any
- final def getClass(): Class[_ <: AnyRef]
- Definition Classes
- AnyRef → Any
- Annotations
- @HotSpotIntrinsicCandidate() @native()
- def hashCode(): Int
- Definition Classes
- AnyRef → Any
- Annotations
- @HotSpotIntrinsicCandidate() @native()
- final def isInstanceOf[T0]: Boolean
- Definition Classes
- Any
- final def ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- final def notify(): Unit
- Definition Classes
- AnyRef
- Annotations
- @HotSpotIntrinsicCandidate() @native()
- final def notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @HotSpotIntrinsicCandidate() @native()
- def postRestart(reason: Throwable): Unit
User overridable callback: By default it calls
preStart()
.User overridable callback: By default it calls
preStart()
.- reason
the Throwable that caused the restart to happen Is called right AFTER restart on the newly created Actor to allow reinitialization after an Actor crash.
- Annotations
- @throws(classOf[Exception])
- def postStop(): Unit
User overridable callback.
User overridable callback.
Is called asynchronously after 'actor.stop()' is invoked. Empty default implementation.
- Annotations
- @throws(classOf[Exception])
- def preRestart(reason: Throwable, message: Option[Any]): Unit
Scala API: User overridable callback: By default it disposes of all children and then calls
postStop()
.Scala API: User overridable callback: By default it disposes of all children and then calls
postStop()
.- reason
the Throwable that caused the restart to happen
- message
optionally the current message the actor processed when failing, if applicable Is called on a crashed Actor right BEFORE it is restarted to allow clean up of resources before Actor is terminated.
- Annotations
- @throws(classOf[Exception])
- def preStart(): Unit
User overridable callback.
User overridable callback.
Is called when an Actor is started. Actors are automatically started asynchronously when created. Empty default implementation.
- Annotations
- @throws(classOf[Exception])
- implicit final val self: ActorRef
The 'self' field holds the ActorRef for this actor.
The 'self' field holds the ActorRef for this actor.
Can be used to send messages to itself:
self ! message
- final def sender(): ActorRef
The reference sender Actor of the last received message.
The reference sender Actor of the last received message. Is defined if the message was sent from another Actor, else
deadLetters
in pekko.actor.ActorSystem.WARNING: Only valid within the Actor itself, so do not close over it and publish it to other threads!
- def supervisorStrategy: SupervisorStrategy
User overridable definition the strategy to use for supervising child actors.
- final def synchronized[T0](arg0: => T0): T0
- Definition Classes
- AnyRef
- def toString(): String
- Definition Classes
- AnyRef → Any
- def unhandled(message: Any): Unit
User overridable callback.
User overridable callback.
Is called when a message isn't handled by the current behavior of the actor by default it fails with either a pekko.actor.DeathPactException (in case of an unhandled pekko.actor.Terminated message) or publishes an pekko.actor.UnhandledMessage to the actor's system's pekko.event.EventStream
- final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException]) @native()
- final def wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
Deprecated Value Members
- def finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.Throwable]) @Deprecated
- Deprecated
(Since version 9)
- def formatted(fmtstr: String): String
- Implicit
- This member is added by an implicit conversion from Actor toStringFormat[Actor] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @deprecated @inline()
- Deprecated
(Since version 2.12.16) Use
formatString.format(value)
instead ofvalue.formatted(formatString)
, or use thef""
string interpolator. In Java 15 and later,formatted
resolves to the new method in String which has reversed parameters.
- def →[B](y: B): (Actor, B)
- Implicit
- This member is added by an implicit conversion from Actor toArrowAssoc[Actor] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use
->
instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.