com.lightbend.lagom.javadsl.broker

Class TopicProducer

Object

com.lightbend.lagom.javadsl.broker.TopicProducer

public final class TopicProducer
extends Object

Creates topic producers. This can be used to help implement Topic calls on services, a service that returns these topics will automatically have these streams published while the service is running, sharded across the services nodes.

Constructor Summary

Constructors

Constructor and Description
TopicProducer()

Method Summary

Modifier and Type	Method and Description
static <Message> Topic<Message>	singleStreamWithOffset(Function<Offset,akka.stream.javadsl.Source<akka.japi.Pair<Message,Offset>,?>> eventStream) Publish a single stream.
static <Message,Event extends AggregateEvent<Event>> Topic<Message>	taggedStreamWithOffset(org.pcollections.PSequence<AggregateEventTag<Event>> tags, BiFunction<AggregateEventTag<Event>,Offset,akka.stream.javadsl.Source<akka.japi.Pair<Message,Offset>,?>> eventStream) Publish a stream that is sharded across many tags.

Methods inherited from class Object

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

Constructor Detail

TopicProducer

public TopicProducer()

Method Detail

singleStreamWithOffset

public static <Message> Topic<Message> singleStreamWithOffset(Function<Offset,akka.stream.javadsl.Source<akka.japi.Pair<Message,Offset>,?>> eventStream)

Publish a single stream. This producer will ensure every element from the stream will be published at least once (usually only once), using the message offsets to track where in the stream the producer is up to publishing.

Parameters:

eventStream - A function to create the event stream given the last offset that was published.

Returns:

The topic producer.

taggedStreamWithOffset

public static <Message,Event extends AggregateEvent<Event>> Topic<Message> taggedStreamWithOffset(org.pcollections.PSequence<AggregateEventTag<Event>> tags,
                                                                                                  BiFunction<AggregateEventTag<Event>,Offset,akka.stream.javadsl.Source<akka.japi.Pair<Message,Offset>,?>> eventStream)

Publish a stream that is sharded across many tags. The tags will be distributed around the cluster, ensuring that at most one event stream for each tag is being published at a particular time. This producer will ensure every element from each tags stream will be published at least once (usually only once), using the message offsets to track where in the stream the producer is up to publishing.

Parameters:

tags - The tags to publish.

eventStream - A function event stream for a given shard given the last offset that was published.

Returns:

The topic producer.