# Package org.apache.storm.state

- Interface Summary
  Interface | Description
  --- | ---
  IStateSpout |
  IStateSpoutOutputCollector |
  ISubscribedState |
  ISynchronizeOutputCollector |
  KeyValueState<K,​V> | A state that supports key-value mappings.
  Serializer<T> | Interface to be implemented for serlializing and de-serializing the state.
  State | The state of the component that is either managed by the framework (e.g in case of `IStatefulBolt`) or managed by the the individual components themselves.
  StateEncoder<K,​V,​KENCODEDT,​VENCODEDT> | The interface of State Encoder.
  StateProvider | Used by the `StateFactory` to create a new state instances.

- Class Summary
  Class | Description
  --- | ---
  BaseBinaryStateIterator<K,​V> | Base implementation of iterator over `KeyValueState` which encoded types of key and value are both binary type.
  BaseStateIterator<K,​V,​KENCODEDT,​VENCODEDT> | Base implementation of iterator over `KeyValueState`.
  DefaultStateEncoder<K,​V> | Default state encoder class for encoding/decoding key values.
  DefaultStateSerializer<T> | A default implementation that uses Kryo to serialize and de-serialize the state.
  InMemoryKeyValueState<K,​V> | An in-memory implementation of the `State`.
  InMemoryKeyValueStateProvider | Provides `InMemoryKeyValueState`.
  StateFactory | A factory for creating `State` instances.
  StateSpoutOutputCollector |
  SynchronizeOutputCollector |