Pair.java

/**
 * The contents of this file are subject to the license and copyright
 * detailed in the LICENSE file at the root of the source
 * tree and available online at
 *
 * https://github.com/keeps/roda
 */
package org.roda.core.data.v2.common;

public class Pair<K, V> {

  private K first;
  private V second;

  public Pair() {
    super();
  }

  /**
   * Instead of using this construtor, the of function should be used
   */
  public Pair(K first, V second) {
    this.first = first;
    this.second = second;
  }

  public static <K, V> Pair<K, V> of(K key, V value) {
    return new Pair<>(key, value);
  }

  public K getFirst() {
    return this.first;
  }

  public void setFirst(K value) {
    this.first = value;
  }

  public V getSecond() {
    return this.second;
  }

  public void setSecond(V value) {
    this.second = value;
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((first == null) ? 0 : first.hashCode());
    result = prime * result + ((second == null) ? 0 : second.hashCode());
    return result;
  }

  @Override
  public String toString() {
    return "(" + first + ", " + second + ")";
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj == null) {
      return false;
    }
    if (!(obj instanceof Pair)) {
      return false;
    }
    Pair<?, ?> other = (Pair<?, ?>) obj;
    if (first == null) {
      if (other.first != null) {
        return false;
      }
    } else if (!first.equals(other.first)) {
      return false;
    }
    if (second == null) {
      if (other.second != null) {
        return false;
      }
    } else if (!second.equals(other.second)) {
      return false;
    }
    return true;
  }

}