Ptidej-v5.2-master/Ptidej Reporting Tests/src/net/sf/jasperreports/engine/util/Pair.java
/*
 * ============================================================================
 * GNU Lesser General Public License
 * ============================================================================
 *
 * JasperReports - Free Java report-generating library.
 * Copyright (C) 2001-2006 JasperSoft Corporation http://www.jaspersoft.com
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
 * 
 * JasperSoft Corporation
 * 303 Second Street, Suite 450 North
 * San Francisco, CA 94107
 * http://www.jaspersoft.com
 */
package net.sf.jasperreports.engine.util;

import java.io.Serializable;


/**
 * Utility class used to pair two objects.
 * 
 * @author Lucian Chirita (lucianc@users.sourceforge.net)
 * @version $Id: Pair.java,v 1.1 2008/09/29 16:20:17 guehene Exp $
 */
public class Pair implements Serializable
{
	private static final long serialVersionUID = 1; //too late to replace this now
	
	private final Object o1;
	private final Object o2;
	private final int hash;

	
	/**
	 * Create a pair instance.
	 * 
	 * @param o1 the first member of the pair
	 * @param o2 the second member of the pair
	 */
	public Pair(Object o1, Object o2)
	{
		this.o1 = o1;
		this.o2 = o2;
		this.hash = computeHash();
	}

	private int computeHash()
	{
		int hashCode = this.o1 == null ? 0 : this.o1.hashCode();
		hashCode *= 31;
		hashCode += this.o2 == null ? 0 : this.o2.hashCode();
		return hashCode;
	}

	public boolean equals(Object o)
	{
		if (o == this)
		{
			return true;
		}
		
		if (o == null || !(o instanceof Pair))
		{
			return false;
		}
		
		Pair p = (Pair) o;
		
		return (p.o1 == null ? this.o1 == null : (this.o1 != null && p.o1.equals(this.o1))) &&
			(p.o2 == null ? this.o2 == null : (this.o2 != null && p.o2.equals(this.o2)));
	}

	public int hashCode()
	{
		return this.hash;
	}
	
	public String toString()
	{
		return "(" + String.valueOf(this.o1) + ", " + String.valueOf(this.o2) + ")";
	}

}
