# Package org.apache.storm.spout

- Interface Summary
  Interface | Description
  --- | ---
  IMultiSchemableSpout |
  ISchemableSpout |
  ISpout | ISpout is the core interface for implementing spouts.
  ISpoutOutputCollector | Methods are not expected to be thread safe.
  MultiScheme |
  Scheme |

- Class Summary
  Class | Description
  --- | ---
  CheckpointSpout | Emits checkpoint tuples which is used to save the state of the `IStatefulComponent` across the topology.
  CheckPointState | Captures the current state of the transaction in `CheckpointSpout`.
  RawMultiScheme |
  RawScheme |
  SchemeAsMultiScheme |
  ShellSpout |
  SpoutOutputCollector | This output collector exposes the API for emitting tuples from an `IRichSpout`.

- Enum Summary
  Enum | Description
  --- | ---
  CheckPointState.Action |
  CheckPointState.State |