/* ========================================================================
* JCommon : a free general purpose class library for the Java(tm) platform
* ========================================================================
*
* (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jcommon/index.html
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* --------------
* SortOrder.java
* --------------
* (C) Copyright 2003, 2004, by Object Refinery Limited.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* $Id: SortOrder.java,v 1.6 2005/10/18 13:24:19 mungady Exp $
*
* Changes:
* --------
* 05-Mar-2003 : Version 1 (DG);
* 13-Mar-2003 : Implemented Serializable (DG);
* 27-Aug-2003 : Moved from JFreeChart --> JCommon (DG);
* 29-Jul-2004 : Fixed error in readResolve() method (DG);
*
*/
package org.jfree.util;
import java.io.ObjectStreamException;
import java.io.Serializable;
/**
* Defines tokens used to indicate sorting order (ascending or descending).
*
* @author David Gilbert
*/
public final class SortOrder implements Serializable {
/** For serialization. */
private static final long serialVersionUID = -2124469847758108312L;
/** Ascending order. */
public static final SortOrder ASCENDING
= new SortOrder("SortOrder.ASCENDING");
/** Descending order. */
public static final SortOrder DESCENDING
= new SortOrder("SortOrder.DESCENDING");
/** The name. */
private String name;
/**
* Private constructor.
*
* @param name the name.
*/
private SortOrder(final String name) {
this.name = name;
}
/**
* Returns a string representing the object.
*
* @return The string.
*/
public String toString() {
return this.name;
}
/**
* Returns <code>true</code> if this object is equal to the specified
* object, and <code>false</code> otherwise.
*
* @param obj the other object.
*
* @return A boolean.
*/
public boolean equals(final Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof SortOrder)) {
return false;
}
final SortOrder that = (SortOrder) obj;
if (!this.name.equals(that.toString())) {
return false;
}
return true;
}
/**
* Returns a hash code value for the object.
*
* @return The hashcode
*/
public int hashCode() {
return this.name.hashCode();
}
/**
* Ensures that serialization returns the unique instances.
*
* @return The object.
*
* @throws ObjectStreamException if there is a problem.
*/
private Object readResolve() throws ObjectStreamException {
if (this.equals(SortOrder.ASCENDING)) {
return SortOrder.ASCENDING;
}
else if (this.equals(SortOrder.DESCENDING)) {
return SortOrder.DESCENDING;
}
return null;
}
}