ShardRegion.MessageExtractor

All Known Implementing Classes:

ShardRegion.HashCodeMessageExtractor

Enclosing class:

ShardRegion
```
public static interface ShardRegion.MessageExtractor
```
Java API: Interface of functions to extract entity id, shard id, and the message to send to the entity from an incoming message.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`java.lang.String`	`entityId(java.lang.Object message)`	Extract the entity id from an incoming `message`.
`java.lang.Object`	`entityMessage(java.lang.Object message)`	Extract the message to send to the entity from an incoming `message`.
`java.lang.String`	`shardId(java.lang.Object message)`	Extract the shard id from an incoming `message`.

- Method Detail
  - entityId
```
java.lang.String entityId(java.lang.Object message)
```
    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
  - entityMessage
```
java.lang.Object entityMessage(java.lang.Object message)
```
    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.
  - shardId
```
java.lang.String shardId(java.lang.Object message)
```
    Extract the shard id from an incoming message. Only messages that passed the entityId(java.lang.Object) function will be used as input to this function.