001: /* ========================================================================
002: * JCommon : a free general purpose class library for the Java(tm) platform
003: * ========================================================================
004: *
005: * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006: *
007: * Project Info: http://www.jfree.org/jcommon/index.html
008: *
009: * This library is free software; you can redistribute it and/or modify it
010: * under the terms of the GNU Lesser General Public License as published by
011: * the Free Software Foundation; either version 2.1 of the License, or
012: * (at your option) any later version.
013: *
014: * This library is distributed in the hope that it will be useful, but
015: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017: * License for more details.
018: *
019: * You should have received a copy of the GNU Lesser General Public
020: * License along with this library; if not, write to the Free Software
021: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022: * USA.
023: *
024: * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025: * in the United States and other countries.]
026: *
027: * --------------
028: * SortOrder.java
029: * --------------
030: * (C) Copyright 2003, 2004, by Object Refinery Limited.
031: *
032: * Original Author: David Gilbert (for Object Refinery Limited);
033: * Contributor(s): -;
034: *
035: * $Id: SortOrder.java,v 1.6 2005/10/18 13:24:19 mungady Exp $
036: *
037: * Changes:
038: * --------
039: * 05-Mar-2003 : Version 1 (DG);
040: * 13-Mar-2003 : Implemented Serializable (DG);
041: * 27-Aug-2003 : Moved from JFreeChart --> JCommon (DG);
042: * 29-Jul-2004 : Fixed error in readResolve() method (DG);
043: *
044: */
045:
046: package org.jfree.util;
047:
048: import java.io.ObjectStreamException;
049: import java.io.Serializable;
050:
051: /**
052: * Defines tokens used to indicate sorting order (ascending or descending).
053: *
054: * @author David Gilbert
055: */
056: public final class SortOrder implements Serializable {
057:
058: /** For serialization. */
059: private static final long serialVersionUID = -2124469847758108312L;
060:
061: /** Ascending order. */
062: public static final SortOrder ASCENDING = new SortOrder(
063: "SortOrder.ASCENDING");
064:
065: /** Descending order. */
066: public static final SortOrder DESCENDING = new SortOrder(
067: "SortOrder.DESCENDING");
068:
069: /** The name. */
070: private String name;
071:
072: /**
073: * Private constructor.
074: *
075: * @param name the name.
076: */
077: private SortOrder(final String name) {
078: this .name = name;
079: }
080:
081: /**
082: * Returns a string representing the object.
083: *
084: * @return The string.
085: */
086: public String toString() {
087: return this .name;
088: }
089:
090: /**
091: * Returns <code>true</code> if this object is equal to the specified
092: * object, and <code>false</code> otherwise.
093: *
094: * @param obj the other object.
095: *
096: * @return A boolean.
097: */
098: public boolean equals(final Object obj) {
099:
100: if (this == obj) {
101: return true;
102: }
103: if (!(obj instanceof SortOrder)) {
104: return false;
105: }
106:
107: final SortOrder that = (SortOrder) obj;
108: if (!this .name.equals(that.toString())) {
109: return false;
110: }
111:
112: return true;
113: }
114:
115: /**
116: * Returns a hash code value for the object.
117: *
118: * @return The hashcode
119: */
120: public int hashCode() {
121: return this .name.hashCode();
122: }
123:
124: /**
125: * Ensures that serialization returns the unique instances.
126: *
127: * @return The object.
128: *
129: * @throws ObjectStreamException if there is a problem.
130: */
131: private Object readResolve() throws ObjectStreamException {
132: if (this.equals(SortOrder.ASCENDING)) {
133: return SortOrder.ASCENDING;
134: } else if (this.equals(SortOrder.DESCENDING)) {
135: return SortOrder.DESCENDING;
136: }
137: return null;
138: }
139: }
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