# Package org.apache.storm.spout

package org.apache.storm.spout

- Related Packages
  Package
  Description
  org.apache.storm
- 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`.
  CheckPointState.Action
  CheckPointState.State
  IMultiSchemableSpout
  ISchemableSpout
  ISpout
  ISpout is the core interface for implementing spouts.
  ISpoutOutputCollector
  Methods are not expected to be thread safe.
  MultiScheme
  RawMultiScheme
  RawScheme
  Scheme
  SchemeAsMultiScheme
  ShellSpout
  SpoutOutputCollector
  This output collector exposes the API for emitting tuples from an `IRichSpout`.