Package akka.cluster.sharding.typed.javadsl

Class Entity<M,E>

java.lang.Object

akka.cluster.sharding.typed.javadsl.Entity<M,E>

public final class Entity<M,E>
extends java.lang.Object

Props of the entity actors, such as dispatcher settings.

Constructor Summary

Constructors

Constructor	Description
Entity()

Method Summary

Modifier and Type	Method	Description
java.util.Optional<ShardCoordinator.ShardAllocationStrategy>	allocationStrategy()
Function<EntityContext<M>,Behavior<M>>	createBehavior()
Props	entityProps()
java.util.Optional<ShardingMessageExtractor<E,M>>	messageExtractor()
static <M> Entity<M,ShardingEnvelope<M>>	of(EntityTypeKey<M> typeKey, Function<EntityContext<M>,Behavior<M>> createBehavior)
static <Command,Event,State> Entity<Command,ShardingEnvelope<Command>>	ofPersistentEntity(EntityTypeKey<Command> typeKey, Function<EntityContext<Command>,EventSourcedEntity<Command,Event,State>> createPersistentEntity)	Defines how the EventSourcedEntity should be created.
java.util.Optional<ClusterShardingSettings>	settings()
java.util.Optional<M>	stopMessage()
EntityTypeKey<M>	typeKey()
Entity<M,E>	withAllocationStrategy(ShardCoordinator.ShardAllocationStrategy newAllocationStrategy)	Allocation strategy which decides on which nodes to allocate new shards, ClusterSharding.defaultShardAllocationStrategy(akka.cluster.sharding.typed.ClusterShardingSettings) is used if this is not specified.
Entity<M,E>	withEntityProps(Props newEntityProps)
<Envelope> Entity<M,Envelope>	withMessageExtractor(ShardingMessageExtractor<Envelope,M> newExtractor)	If a messageExtractor is not specified the messages are sent to the entities by wrapping them in ShardingEnvelope with the entityId of the recipient actor.
Entity<M,E>	withSettings(ClusterShardingSettings newSettings)	Additional settings, typically loaded from configuration.
Entity<M,E>	withStopMessage(M newStopMessage)	Message sent to an entity to tell it to stop, e.g.

Methods inherited from class java.lang.Object

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

Constructor Detail

Entity

public Entity()

Method Detail

of

public static <M> Entity<M,ShardingEnvelope<M>> of(EntityTypeKey<M> typeKey,
                                                         Function<EntityContext<M>,Behavior<M>> createBehavior)

ofPersistentEntity

public static <Command,Event,State> Entity<Command,ShardingEnvelope<Command>> ofPersistentEntity(EntityTypeKey<Command> typeKey,
                                                                                                                   Function<EntityContext<Command>,EventSourcedEntity<Command,Event,State>> createPersistentEntity)

Defines how the EventSourcedEntity should be created. Used in ClusterSharding.init(akka.cluster.sharding.typed.javadsl.Entity<M, E>). Any Behavior can be used as a sharded entity actor, but the combination of sharding and persistent actors is very common and therefore this factory is provided as convenience.

More optional settings can be defined using the with methods of the returned Entity.

Parameters:

typeKey - A key that uniquely identifies the type of entity in this cluster

createPersistentEntity - Create the PersistentEntity for an entity given a EntityContext (includes entityId)

Returns:

(undocumented)

createBehavior

public Function<EntityContext<M>,Behavior<M>> createBehavior()

typeKey

public EntityTypeKey<M> typeKey()

stopMessage

public java.util.Optional<M> stopMessage()

entityProps

public Props entityProps()

settings

public java.util.Optional<ClusterShardingSettings> settings()

messageExtractor

public java.util.Optional<ShardingMessageExtractor<E,M>> messageExtractor()

allocationStrategy

public java.util.Optional<ShardCoordinator.ShardAllocationStrategy> allocationStrategy()

withEntityProps

public Entity<M,E> withEntityProps(Props newEntityProps)

withSettings

public Entity<M,E> withSettings(ClusterShardingSettings newSettings)

Additional settings, typically loaded from configuration.

Parameters:

newSettings - (undocumented)

Returns:

(undocumented)

withStopMessage

public Entity<M,E> withStopMessage(M newStopMessage)

Message sent to an entity to tell it to stop, e.g. when rebalanced or passivated. If this is not defined it will be stopped automatically. It can be useful to define a custom stop message if the entity needs to perform some asynchronous cleanup or interactions before stopping.

Parameters:

newStopMessage - (undocumented)

Returns:

(undocumented)

withMessageExtractor

public <Envelope> Entity<M,Envelope> withMessageExtractor(ShardingMessageExtractor<Envelope,M> newExtractor)

If a messageExtractor is not specified the messages are sent to the entities by wrapping them in ShardingEnvelope with the entityId of the recipient actor. That envelope is used by the HashCodeMessageExtractor for extracting entityId and shardId. The number of shards is then defined by numberOfShards in ClusterShardingSettings, which by default is configured with akka.cluster.sharding.number-of-shards.

Parameters:

newExtractor - (undocumented)

Returns:

(undocumented)

withAllocationStrategy

public Entity<M,E> withAllocationStrategy(ShardCoordinator.ShardAllocationStrategy newAllocationStrategy)

Allocation strategy which decides on which nodes to allocate new shards, ClusterSharding.defaultShardAllocationStrategy(akka.cluster.sharding.typed.ClusterShardingSettings) is used if this is not specified.

Parameters:

newAllocationStrategy - (undocumented)

Returns:

(undocumented)