com.lightbend.lagom.javadsl.persistence.cassandra
Mutable builder for defining event handlers.
The processed events belong to a com.lightbend.lagom.javadsl.persistence.AggregateEventTag that is specified by this method, e.g.
The processed events belong to a com.lightbend.lagom.javadsl.persistence.AggregateEventTag
that is specified by this method, e.g. all persistent events of all Order
entities.
Define the event handlers that are to be used.
Define the event handlers that are to be used. Use the supplied
builder
to define the event handlers. One handler for each event class.
A handler is a BiFunction
that takes the event and the offset as
parameters and returns zero or more bound statements that will be executed
before processing next event.
First you must tell where in the event stream the processing should start, i.e.
First you must tell where in the event stream the processing should start,
i.e. return the offset. The current offset is a parameter to the event
handler for each event and it should typically be stored so that it can be
restored with a select
statement here. Use the CassandraSession
to get the stored offset.
Other things that is typically performed in this method is to create prepared statements that are later used when processing the events. Use CassandraSession#prepare to create the prepared statements.
Return #noOffset if you want to processes all events, e.g. when starting the first time or if the number of events are known to be small enough to processes all events.
Convenience method to create an already completed CompletionStage
with one BoundStatement
.
Convenience method to create an already completed CompletionStage
with several BoundStatement
.
Convenience method to create an already completed CompletionStage
with zero BoundStatement
.
Consume events produced by com.lightbend.lagom.javadsl.persistence.PersistentEntity instances and update one or more tables in Cassandra that are optimized for queries. The events belong to a com.lightbend.lagom.javadsl.persistence.AggregateEventTag, e.g. all persistent events of all
Order
entities.(Since version 1.2.0) Use ReadSideProcessor instead with CassandraReadSide builder