trait Handler[Envelope] extends HandlerLifecycle

Implement this interface for the Envelope handler in the Projection. Some projections may have more specific handler types.

It can be stateful, with variables and mutable data structures. It is invoked by the Projection machinery one envelope at a time and visibility guarantees between the invocations are handled automatically, i.e. no volatile or other concurrency primitives are needed for managing the state.

Supported error handling strategies for when processing an Envelope fails can be defined in configuration or using the withRecoveryStrategy method of a Projection implementation.

Annotations
@ApiMayChange()
Source
Handler.scala
Linear Supertypes
HandlerLifecycle, AnyRef, Any
Known Subclasses
ActorHandler, StatefulHandler
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Inherited
  1. Handler
  2. HandlerLifecycle
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Visibility
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  2. Protected

Abstract Value Members

  1. abstract def process(envelope: Envelope): Future[Done]

    The process method is invoked for each Envelope.

    The process method is invoked for each Envelope. One envelope is processed at a time. The returned Future is to be completed when the processing of the envelope has finished. It will not be invoked with the next envelope until after the returned Future has been completed.

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##: Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  5. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  6. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  7. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  8. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable])
  9. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  10. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  11. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  12. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  13. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  14. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  15. def start(): Future[Done]

    Invoked when the projection is starting, before first envelope is processed.

    Invoked when the projection is starting, before first envelope is processed. Can be overridden to implement initialization. It is also called when the Projection is restarted after a failure.

    Definition Classes
    HandlerLifecycle
  16. def stop(): Future[Done]

    Invoked when the projection has been stopped.

    Invoked when the projection has been stopped. Can be overridden to implement resource cleanup. It is also called when the Projection is restarted after a failure.

    Definition Classes
    HandlerLifecycle
  17. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  18. def toString(): String
    Definition Classes
    AnyRef → Any
  19. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  20. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  21. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()

Inherited from HandlerLifecycle

Inherited from AnyRef

Inherited from Any

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