lang/java/reef-common/src/main/java/org/apache/reef/io/Tuple.java

/*
 * 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.reef.io;

import org.apache.reef.annotations.Unstable;

/**
 * A key-value pair of elements.
 */
@Unstable
public final class Tuple<K, V> {
  private final K k;
  private final V v;

  public Tuple(final K k, final V v) {
    this.k = k;
    this.v = v;
  }

  public K getKey() {
    return k;
  }

  public V getValue() {
    return v;
  }

  @Override
  public boolean equals(final Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }

    final Tuple tuple = (Tuple) o;

    if (!k.equals(tuple.k)) {
      return false;
    }
    if (!v.equals(tuple.v)) {
      return false;
    }

    return true;
  }

  @Override
  public int hashCode() {
    int result = k.hashCode();
    result = 31 * result + v.hashCode();
    return result;
  }

  @Override
  public String toString() {
    return "(" + getKey() + "," + getValue() + ")";
  }

}