Package org.apache.pekko.actor.typed.javadsl

Class AbstractMatchingBehavior<T>

java.lang.Object
org.apache.pekko.actor.typed.Behavior<T>
org.apache.pekko.actor.typed.ExtensibleBehavior<T>
org.apache.pekko.actor.typed.javadsl.AbstractMatchingBehavior<T>
public abstract class AbstractMatchingBehavior<T> extends ExtensibleBehavior<T>
An actor Behavior can be implemented by extending this class and implementing the abstract method onMessage(T). Mutable state can be defined as instance variables of the class.

This is an object-oriented style of defining a Behavior. A more functional style alternative is provided by the factory methods in Behaviors, for example Behaviors.receiveMessage.

An alternative object-oriented style is found in AbstractBehavior, which uses builders to define the Behavior. In contrast to extending AbstractBehavior, extending this class should have reduced overhead, though depending on the complexity of the protocol handled by this actor and on the Java version in use, the onMessage and onSignal methods may be overly complex.

Instances of this behavior should be created via Behaviors.setup and the ActorContext should be passed as a constructor parameter from the factory function. This is important because a new instance should be created when restart supervision is used.

When switching behavior to another behavior which requires a context, the original ActorContext can be used or a Behaviors.setup can be used: either will end up using the same ActorContext instance.

It must not be created with an ActorContext of another actor (e.g. the parent actor). Doing so will be detected at runtime and throw an IllegalStateException when the first message is received.

See Also:
  • Behaviors.setup

  • Constructor Details

    • AbstractMatchingBehavior

      public AbstractMatchingBehavior(ActorContext<T> context)

  • Method Details

    • getContext

      protected final ActorContext<T> getContext()

    • onMessage

      public abstract Behavior<T> onMessage(T message) throws Exception
      Implement this to define how messages are processed. To indicate no change in behavior beyond changes due to updating instance variables of this class, one may return either this or Behaviors.same.
      Throws:
      Exception

    • onSignal

      public Behavior<T> onSignal(Signal signal) throws Exception
      Override this to handle a signal. The default implementation handles only MessageAdaptionFailure and otherwise ignores the signal.
      Throws:
      Exception

    • receive

      public final Behavior<T> receive(TypedActorContext<T> ctx, T msg) throws Exception
      Description copied from class: ExtensibleBehavior
      Process an incoming message and return the next behavior.

      The returned behavior can in addition to normal behaviors be one of the canned special objects:

      * returning stopped will terminate this Behavior * returning same designates to reuse the current Behavior * returning unhandled keeps the same Behavior and signals that the message was not yet handled

      Code calling this method should use Behavior$ canonicalize to replace the special objects with real Behaviors.

      Specified by:
      receive in class ExtensibleBehavior<T>
      Throws:
      Exception

    • receiveSignal

      public final Behavior<T> receiveSignal(TypedActorContext<T> ctx, Signal signal) throws Exception
      Description copied from class: ExtensibleBehavior
      Process an incoming Signal and return the next behavior. This means that all lifecycle hooks, ReceiveTimeout, Terminated and Failed messages can initiate a behavior change.

      The returned behavior can in addition to normal behaviors be one of the canned special objects:

      * returning stopped will terminate this Behavior * returning same designates to reuse the current Behavior * returning unhandled keeps the same Behavior and signals that the message was not yet handled

      Code calling this method should use Behavior$ canonicalize to replace the special objects with real Behaviors.

      Specified by:
      receiveSignal in class ExtensibleBehavior<T>
      Throws:
      Exception