Tuple.java

/*
 * Part of the CCNx Java Library.
 *
 * Copyright (C) 2008, 2009, 2010 Palo Alto Research Center, Inc.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation. 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details. You should have received
 * a copy of the GNU Lesser General Public License along with this library;
 * if not, write to the Free Software Foundation, Inc., 51 Franklin Street,
 * Fifth Floor, Boston, MA 02110-1301 USA.
 */
package org.ccnx.ccn.impl.support;

/**
 * Utility class to represent pairs of objects, most commonly as return
 * values from methods.
 */
public class Tuple<A, B> {
	
	A _first;
	B _second;
	
	public Tuple(A first, B second) {
		_first = first;
		_second = second;
	}
	
	public A first() { return _first; }
	public B second() { return _second; }
	public void setFirst(A first) { _first = first; }
	public void setSecond(B second) { _second = second; }

	@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 boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Tuple<?,?> other = (Tuple<?,?>) 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;
	}
}