ClusterSharding

java.lang.Object
- akka.cluster.sharding.typed.javadsl.ClusterSharding

Type Parameters:

M - The type of message the entity accepts

E - A possible envelope around the message the entity accepts

Direct Known Subclasses:

ClusterShardingImpl
```
public abstract class ClusterSharding
extends java.lang.Object
```
Initialize sharding for the given entity factory settings.
It will start a shard region or a proxy depending on if the settings require role and if this node has such a role.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`ClusterSharding.Passivate<M>`
`static class`	`ClusterSharding.Passivate$`
`static interface`	`ClusterSharding.ShardCommand`	When an entity is created an `ActorRef[ShardCommand]` is passed to the factory method.

Constructor Summary

Constructors
Constructor Description

ClusterSharding()

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`abstract ShardCoordinator.ShardAllocationStrategy`	`defaultShardAllocationStrategy(ClusterShardingSettings settings)`	The default is currently `ShardCoordinator.LeastShardAllocationStrategy` with the given `settings`.
`abstract <M> EntityRef<M>`	`entityRefFor(EntityTypeKey<M> typeKey, java.lang.String entityId)`	Create an `ActorRef`-like reference to a specific sharded entity.
`static ClusterSharding`	`get(ActorSystem<?> system)`
`abstract <M,E> ActorRef<E>`	`init(Entity<M,E> entity)`
`abstract ActorRef<ClusterShardingQuery>`	`shardState()`	Actor for querying Cluster Sharding state

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ClusterSharding
```
public ClusterSharding()
```
- Method Detail
  - get
```
public static ClusterSharding get(ActorSystem<?> system)
```
  - init
```
public abstract <M,E> ActorRef<E> init(Entity<M,E> entity)
```
  - entityRefFor
```
public abstract <M> EntityRef<M> entityRefFor(EntityTypeKey<M> typeKey,
                                              java.lang.String entityId)
```
    Create an ActorRef-like reference to a specific sharded entity. Currently you have to correctly specify the type of messages the target can handle.
    Messages sent through this EntityRef will be wrapped in a ShardingEnvelope including the here provided entityId.
    For in-depth documentation of its semantics, see EntityRef.
    
    Parameters:
    
    typeKey - (undocumented)
    
    entityId - (undocumented)
    
    Returns:
    
    (undocumented)
  - shardState
```
public abstract ActorRef<ClusterShardingQuery> shardState()
```
    Actor for querying Cluster Sharding state
    
    Returns:
    
    (undocumented)
  - defaultShardAllocationStrategy
```
public abstract ShardCoordinator.ShardAllocationStrategy defaultShardAllocationStrategy(ClusterShardingSettings settings)
```
    The default is currently ShardCoordinator.LeastShardAllocationStrategy with the given settings. This could be changed in the future.
    
    Parameters:
    
    settings - (undocumented)
    
    Returns:
    
    (undocumented)