Package org.apache.pekko.cluster.sharding.typed

Class HashCodeMessageExtractor<M>

java.lang.Object

org.apache.pekko.cluster.sharding.typed.ShardingMessageExtractor<ShardingEnvelope<M>,M>

org.apache.pekko.cluster.sharding.typed.HashCodeMessageExtractor<M>

Type Parameters:

M - The type of message accepted by the entity actor

public final class HashCodeMessageExtractor<M>
extends ShardingMessageExtractor<ShardingEnvelope<M>,M>

Default message extractor type, using envelopes to identify what entity a message is for and the hashcode of the entityId to decide which shard an entity belongs to.

This is recommended since it does not force details about sharding into the entity protocol

Constructor Summary

Constructors

Constructor	Description
HashCodeMessageExtractor(int numberOfShards)

Method Summary

Modifier and Type	Method	Description
String	entityId(ShardingEnvelope<M> envelope)	Extract the entity id from an incoming message.
int	numberOfShards()
String	shardId(String entityId)	The shard identifier for a given entity id.
M	unwrapMessage(ShardingEnvelope<M> envelope)	Extract the message to send to the entity from an incoming message.

Methods inherited from class org.apache.pekko.cluster.sharding.typed.ShardingMessageExtractor

apply, noEnvelope

Methods inherited from class java.lang.Object

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

Constructor Details

HashCodeMessageExtractor

public HashCodeMessageExtractor(int numberOfShards)

Method Details

entityId

public String entityId(ShardingEnvelope<M> envelope)

Description copied from class: ShardingMessageExtractor

Extract the entity id from an incoming message. If null is returned the message will be unhandled, i.e. posted as Unhandled messages on the event stream

Specified by:

entityId in class ShardingMessageExtractor<ShardingEnvelope<M>,M>

numberOfShards

public int numberOfShards()

shardId

public String shardId(String entityId)

Description copied from class: ShardingMessageExtractor

The shard identifier for a given entity id. Only messages that passed the ShardingMessageExtractor.entityId(E) function will be used as input to this function.

Specified by:

shardId in class ShardingMessageExtractor<ShardingEnvelope<M>,M>

unwrapMessage

public M unwrapMessage(ShardingEnvelope<M> envelope)

Description copied from class: ShardingMessageExtractor

Extract the message to send to the entity from an incoming message. Note that the extracted message does not have to be the same as the incoming message to support wrapping in message envelope that is unwrapped before sending to the entity actor.

Specified by:

unwrapMessage in class ShardingMessageExtractor<ShardingEnvelope<M>,M>