# Uses of Interface
org.apache.storm.state.State

Packages that use State
Package
Description
org.apache.storm.redis.state
org.apache.storm.state
org.apache.storm.topology
org.apache.storm.topology.base

- ## Uses of State in org.apache.storm.redis.state

  Classes in org.apache.storm.redis.state that implement State
  Modifier and Type
  Class
  Description
  `class`
  `RedisKeyValueState<K,V>`
  A redis based implementation that persists the state in Redis.
  Methods in org.apache.storm.redis.state that return State
  Modifier and Type
  Method
  Description
  `State`
  RedisKeyValueStateProvider.`newState(String namespace, Map<String,Object> topoConf, TopologyContext context)`

- ## Uses of State in org.apache.storm.state

  Subinterfaces of State in org.apache.storm.state
  Modifier and Type
  Interface
  Description
  `interface`
  `KeyValueState<K,V>`
  A state that supports key-value mappings.
  Classes in org.apache.storm.state that implement State
  Modifier and Type
  Class
  Description
  `class`
  `InMemoryKeyValueState<K,V>`
  An in-memory implementation of the `State`.
  Methods in org.apache.storm.state that return State
  Modifier and Type
  Method
  Description
  `static State`
  StateFactory.`getState(String namespace, Map<String,Object> topoConf, TopologyContext context)`
  Returns a new state instance using the `Config.TOPOLOGY_STATE_PROVIDER` or a `InMemoryKeyValueState` if no provider is configured.
  `State`
  InMemoryKeyValueStateProvider.`newState(String namespace, Map<String,Object> topoConf, TopologyContext context)`
  `State`
  StateProvider.`newState(String namespace, Map<String,Object> topoConf, TopologyContext context)`
  Returns a new state instance.

- ## Uses of State in org.apache.storm.topology

  Classes in org.apache.storm.topology with type parameters of type State
  Modifier and Type
  Interface
  Description
  `interface`
  `IStatefulBolt<T extends State>`
  A bolt abstraction for supporting stateful computation.
  `interface`
  `IStatefulComponent<T extends State>`
  Common methods for stateful components in the topology.
  `interface`
  `IStatefulWindowedBolt<T extends State>`
  A windowed bolt abstraction for supporting windowing operation with state.
  `class`
  `PersistentWindowedBoltExecutor<T extends State>`
  Wraps a `IStatefulWindowedBolt` and handles the execution.
  `class`
  `StatefulBoltExecutor<T extends State>`
  Wraps a `IStatefulBolt` and manages the state of the bolt.
  `class`
  `StatefulWindowedBoltExecutor<T extends State>`
  Wraps a `IStatefulWindowedBolt` and handles the execution.
  Methods in org.apache.storm.topology with type parameters of type State
  Modifier and Type
  Method
  Description
  `<T extends State>
  BoltDeclarer`
  TopologyBuilder.`setBolt(String id, IStatefulBolt<T> bolt)`
  Define a new bolt in this topology.
  `<T extends State>
  BoltDeclarer`
  TopologyBuilder.`setBolt(String id, IStatefulBolt<T> bolt, Number parallelismHint)`
  Define a new bolt in this topology.
  `<T extends State>
  BoltDeclarer`
  TopologyBuilder.`setBolt(String id, IStatefulWindowedBolt<T> bolt)`
  Define a new bolt in this topology.
  `<T extends State>
  BoltDeclarer`
  TopologyBuilder.`setBolt(String id, IStatefulWindowedBolt<T> bolt, Number parallelismHint)`
  Define a new bolt in this topology.

- ## Uses of State in org.apache.storm.topology.base

  Classes in org.apache.storm.topology.base with type parameters of type State
  Modifier and Type
  Class
  Description
  `class`
  `BaseStatefulBolt<T extends State>`
  `class`
  `BaseStatefulWindowedBolt<T extends State>`