Package akka.cluster.sharding

Class OldCoordinatorStateMigrationEventAdapter

  • All Implemented Interfaces:
    EventAdapter, ReadEventAdapter, WriteEventAdapter
    public final class OldCoordinatorStateMigrationEventAdapter
extends java.lang.Object
implements EventAdapter
    Used for migrating from persistent state store mode to the new event sourced remember entities. No user API, used through configuration. See reference docs for details.

    INTERNAL API

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      EventSeq fromJournal​(java.lang.Object event, java.lang.String manifest)
      Convert a event from its journal model to the applications domain model.
      java.lang.String manifest​(java.lang.Object event)
      Return the manifest (type hint) that will be provided in the fromJournal method.
      java.lang.Object toJournal​(java.lang.Object event)
      Convert domain event to journal event type.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • OldCoordinatorStateMigrationEventAdapter

        public OldCoordinatorStateMigrationEventAdapter()

    • Method Detail

      • fromJournal

        public EventSeq fromJournal​(java.lang.Object event,
                            java.lang.String manifest)
        Description copied from interface: ReadEventAdapter
        Convert a event from its journal model to the applications domain model.

        One event may be adapter into multiple (or none) events which should be delivered to the PersistentActor. Use the specialised EventSeq.single(java.lang.Object) method to emit exactly one event, or EventSeq.empty() in case the adapter is not handling this event. Multiple EventAdapter instances are applied in order as defined in configuration and their emitted event seqs are concatenated and delivered in order to the PersistentActor.

        Specified by:
        fromJournal in interface ReadEventAdapter
        Parameters:
        event - event to be adapted before delivering to the PersistentActor
        manifest - optionally provided manifest (type hint) in case the Adapter has stored one for this event, "" if none
        Returns:
        sequence containing the adapted events (possibly zero) which will be delivered to the PersistentActor

      • manifest

        public java.lang.String manifest​(java.lang.Object event)
        Description copied from interface: WriteEventAdapter
        Return the manifest (type hint) that will be provided in the fromJournal method. Use "" if manifest is not needed.
        Specified by:
        manifest in interface WriteEventAdapter

      • toJournal

        public java.lang.Object toJournal​(java.lang.Object event)
        Description copied from interface: WriteEventAdapter
        Convert domain event to journal event type.

        Some journal may require a specific type to be returned to them, for example if a primary key has to be associated with each event then a journal may require adapters to return com.example.myjournal.EventWithPrimaryKey(event, key).

        The toJournal adaptation must be an 1-to-1 transformation. It is not allowed to drop incoming events during the toJournal adaptation.

        Specified by:
        toJournal in interface WriteEventAdapter
        Parameters:
        event - the application-side domain event to be adapted to the journal model
        Returns:
        the adapted event object, possibly the same object if no adaptation was performed