Package akka.persistence.journal
Interface ReadEventAdapter
-
- All Known Subinterfaces:
EventAdapter
- All Known Implementing Classes:
IdentityEventAdapter$
public interface ReadEventAdapter
Facility to convert from and to specialised data models, as may be required by specialized persistence Journals.Typical use cases include (but are not limited to):
- extracting events from "envelopes"
- manually converting to the Journals storage format, such as JSON, BSON or any specialised binary format
- adapting incoming events from a "data model" to the "domain model"
-
-
Method Summary
All Methods Instance Methods Abstract 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.
-
-
-
Method Detail
-
fromJournal
EventSeq fromJournal(java.lang.Object event, java.lang.String manifest)
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 specialisedEventSeq.single(java.lang.Object)
method to emit exactly one event, orEventSeq.empty()
in case the adapter is not handling this event. MultipleEventAdapter
instances are applied in order as defined in configuration and their emitted event seqs are concatenated and delivered in order to the PersistentActor.- Parameters:
event
- event to be adapted before delivering to the PersistentActormanifest
- 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
-
-