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 org.apache.kafka.streams;
  
  import java.util.Objects;
  
  /**
   * A key-value pair defined for a single Kafka Streams record.
   * If the record comes directly from a Kafka topic then its key/value are defined as the message key/value.
   *
   * @param <K> Key type
   * @param <V> Value type
   */
  public class KeyValue<K, V> {
  
      /** The key of the key-value pair. */
      public final K key;
      /** The value of the key-value pair. */
      public final V value;
  
      /**
       * Create a new key-value pair.
       *
       * @param key   the key
       * @param value the value
       */
      public KeyValue(final K key, final V value) {
          this.key = key;
          this.value = value;
      }
  
      /**
       * Create a new key-value pair.
       *
       * @param key   the key
       * @param value the value
       * @param <K>   the type of the key
       * @param <V>   the type of the value
       * @return a new key-value pair
       */
      public static <K, V> KeyValue<K, V> pair(final K key, final V value) {
          return new KeyValue<>(key, value);
      }
  
      @Override
      public String toString() {
          return "KeyValue(" + key + ", " + value + ")";
      }
  
      @Override
      public boolean equals(final Object obj) {
          if (this == obj) {
              return true;
          }
  
          if (!(obj instanceof KeyValue)) {
              return false;
          }
  
          final KeyValue<?, ?> other = (KeyValue<?, ?>) obj;
          return Objects.equals(key, other.key) && Objects.equals(value, other.value);
      }
  
      @Override
      public int hashCode() {
          return Objects.hash(key, value);
      }
  
  }
  