org.jgrapht.alg.util.Pair Maven / Gradle / Ivy
/*
* (C) Copyright 2015-2021, by Alexey Kudinkin and Contributors.
*
* JGraphT : a free Java graph-theory library
*
* See the CONTRIBUTORS.md file distributed with this work for additional
* information regarding copyright ownership.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0, or the
* GNU Lesser General Public License v2.1 or later
* which is available at
* http://www.gnu.org/licenses/old-licenses/lgpl-2.1-standalone.html.
*
* SPDX-License-Identifier: EPL-2.0 OR LGPL-2.1-or-later
*/
package org.jgrapht.alg.util;
import java.io.*;
import java.util.*;
/**
* Generic pair.
*
* @param the first element type
* @param the second element type
*
*/
public class Pair
implements
Serializable
{
private static final long serialVersionUID = 8176288675989092842L;
/**
* The first pair element
*/
protected A first;
/**
* The second pair element
*/
protected B second;
/**
* Create a new pair
*
* @param a the first element
* @param b the second element
*/
public Pair(A a, B b)
{
this.first = a;
this.second = b;
}
/**
* Get the first element of the pair
*
* @return the first element of the pair
*/
public A getFirst()
{
return first;
}
/**
* Get the second element of the pair
*
* @return the second element of the pair
*/
public B getSecond()
{
return second;
}
/**
* Set the first element of the pair.
*
* @param f the element to be assigned.
*/
public void setFirst(A f)
{
first = f;
}
/**
* Set the second element of the pair.
*
* @param s the element to be assigned.
*/
public void setSecond(B s)
{
second = s;
}
/**
* Assess if this pair contains an element.
*
* @param e The element in question
*
* @return true if contains the element, false otherwise
*
* @param the element type
*/
@SuppressWarnings("unlikely-arg-type")
public boolean hasElement(E e)
{
if (e == null) {
return first == null || second == null;
} else {
return e.equals(first) || e.equals(second);
}
}
@Override
public String toString()
{
return "(" + first + "," + second + ")";
}
@Override
public boolean equals(Object o)
{
if (this == o)
return true;
else if (!(o instanceof Pair))
return false;
@SuppressWarnings("unchecked") Pair other = (Pair) o;
return Objects.equals(first, other.first) && Objects.equals(second, other.second);
}
@Override
public int hashCode()
{
return Objects.hash(first, second);
}
/**
* Create a new pair.
*
* @param a first element
* @param b second element
* @param the first element type
* @param the second element type
* @return new pair
*/
public static Pair of(A a, B b)
{
return new Pair<>(a, b);
}
}