content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package backtype.storm.state;
  
  /**
   * A state that supports key-value mappings.
   */
  public interface KeyValueState<K, V> extends State {
      /**
       * Maps the value with the key
       *
       * @param key   the key
       * @param value the value
       */
      void put(K key, V value);
  
      /**
       * Returns the value mapped to the key
       *
       * @param key the key
       * @return the value or null if no mapping is found
       */
      V get(K key);
  
      /**
       * Returns the value mapped to the key or defaultValue if no mapping is found.
       *
       * @param key          the key
       * @param defaultValue the value to return if no mapping is found
       * @return the value or defaultValue if no mapping is found
       */
      V get(K key, V defaultValue);
  }
  