Package org.apache.storm.state

Interface KeyValueState<K,V>

All Superinterfaces:
Iterable<Map.Entry<K,V>>, State
All Known Implementing Classes:
InMemoryKeyValueState, RedisKeyValueState
public interface KeyValueState<K,V> extends State, Iterable<Map.Entry<K,V>>
A state that supports key-value mappings.

  • Method Summary

    Modifier and Type
    Method
    Description
    V
    delete(K key)
    Deletes the value mapped to the key, if there is any.
    V
    get(K key)
    Returns the value mapped to the key.
    V
    get(K key, V defaultValue)
    Returns the value mapped to the key or defaultValue if no mapping is found.
    void
    put(K key, V value)
    Maps the value with the key.

    Methods inherited from interface java.lang.Iterable

    forEach, iterator, spliterator

    Methods inherited from interface org.apache.storm.state.State

    commit, commit, prepareCommit, rollback

  • Method Details

    • put

      void put(K key, V value)
      Maps the value with the key.
      Parameters:
      key - the key
      value - the value

    • get

      V get(K key)
      Returns the value mapped to the key.
      Parameters:
      key - the key
      Returns:
      the value or null if no mapping is found

    • get

      V get(K key, V defaultValue)
      Returns the value mapped to the key or defaultValue if no mapping is found.
      Parameters:
      key - the key
      defaultValue - the value to return if no mapping is found
      Returns:
      the value or defaultValue if no mapping is found

    • delete

      V delete(K key)
      Deletes the value mapped to the key, if there is any.
      Parameters:
      key - the key