ExtensionId

All Known Implementing Classes:

AbstractExtensionId, ActorRefResolveThreadLocalCache$, AdapterExtension$, AddressTerminatedTopic$, AddressUidExtension$, BoundAddressesExtension$, CallingThreadDispatcherQueues$, CircuitBreakersRegistry$, Clock$, Cluster$, ClusterMetricsExtension$, ClusterSharding$, CoordinatedShutdown$, Discovery$, DistributedData$, DistributedPubSub$, Dns$, DurableStateStoreRegistry$, EventsBySliceFirehose$, EventsourcedInstrumentationProvider$, ExternalShardAllocation$, InMemStorageExtension$, JacksonObjectMapperProvider$, LeaseProvider$, LeaseProvider$, Logging.LogExt$, ManifestInfo$, Persistence$, PersistencePluginProxyExtension$, PersistenceQuery$, PersistenceTestKit.Settings$, RARP$, RecoveryPermitterInstrumentationProvider$, RemotingFlightRecorder$, SerializationExtension$, ShardingFlightRecorder$, SnapshotStorageEmulatorExtension$, SnapshotTestKit.Settings$, StreamRefResolver$, SystemMaterializer$, Tcp$, Tcp$, Tcp$, TestConductor$, TestKitExtension$, Udp$, UdpConnected$
```
public interface ExtensionId<T extends Extension>
```
Identifies an Extension Lookup of Extensions is done by object identity, so the Id must be the same wherever it's used, otherwise you'll get the same extension loaded multiple times.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`T`	`apply(ActorSystem system)`	Returns an instance of the extension identified by this ExtensionId instance.
`T`	`apply(ClassicActorSystemProvider system)`	Returns an instance of the extension identified by this ExtensionId instance.
`T`	`createExtension(ExtendedActorSystem system)`	Is used by Akka to instantiate the Extension identified by this ExtensionId, internal use only.
`boolean`	`equals(java.lang.Object other)`
`T`	`get(ActorSystem system)`	Returns an instance of the extension identified by this ExtensionId instance.
`T`	`get(ClassicActorSystemProvider system)`	Returns an instance of the extension identified by this ExtensionId instance.
`int`	`hashCode()`

- Method Detail
  - apply
```
T apply(ActorSystem system)
```
    Returns an instance of the extension identified by this ExtensionId instance.
  - apply
```
T apply(ClassicActorSystemProvider system)
```
    Returns an instance of the extension identified by this ExtensionId instance.
  - createExtension
```
T createExtension(ExtendedActorSystem system)
```
    Is used by Akka to instantiate the Extension identified by this ExtensionId, internal use only.
  - equals
```
boolean equals(java.lang.Object other)
```
    Overrides:
    
    equals in class java.lang.Object
  - get
```
T get(ActorSystem system)
```
    Returns an instance of the extension identified by this ExtensionId instance. Java API For extensions written in Scala that are to be used from Java also, this method should be overridden to get correct return type.
    override def get(system: ActorSystem): TheExtension = super.get(system)
  - get
```
T get(ClassicActorSystemProvider system)
```
    Returns an instance of the extension identified by this ExtensionId instance. Java API For extensions written in Scala that are to be used from Java also, this method should be overridden to get correct return type.
    override def get(system: ClassicActorSystemProvider): TheExtension = super.get(system)
  - hashCode
```
int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object