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1: /* ======================================================================== 2: * JCommon : a free general purpose class library for the Java(tm) platform 3: * ======================================================================== 4: * 5: * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors. 6: * 7: * Project Info: http://www.jfree.org/jcommon/index.html 8: * 9: * This library is free software; you can redistribute it and/or modify it 10: * under the terms of the GNU Lesser General Public License as published by 11: * the Free Software Foundation; either version 2.1 of the License, or 12: * (at your option) any later version. 13: * 14: * This library is distributed in the hope that it will be useful, but 15: * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 16: * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 17: * License for more details. 18: * 19: * You should have received a copy of the GNU Lesser General Public 20: * License along with this library; if not, write to the Free Software 21: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 22: * USA. 23: * 24: * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 25: * in the United States and other countries.] 26: * 27: * -------------- 28: * SortOrder.java 29: * -------------- 30: * (C) Copyright 2003, 2004, by Object Refinery Limited. 31: * 32: * Original Author: David Gilbert (for Object Refinery Limited); 33: * Contributor(s): -; 34: * 35: * $Id: SortOrder.java,v 1.6 2005/10/18 13:24:19 mungady Exp $ 36: * 37: * Changes: 38: * -------- 39: * 05-Mar-2003 : Version 1 (DG); 40: * 13-Mar-2003 : Implemented Serializable (DG); 41: * 27-Aug-2003 : Moved from JFreeChart --> JCommon (DG); 42: * 29-Jul-2004 : Fixed error in readResolve() method (DG); 43: * 44: */ 45: 46: package org.jfree.util; 47: 48: import java.io.ObjectStreamException; 49: import java.io.Serializable; 50: 51: /** 52: * Defines tokens used to indicate sorting order (ascending or descending). 53: * 54: * @author David Gilbert 55: */ 56: public final class SortOrder implements Serializable { 57: 58: /** For serialization. */ 59: private static final long serialVersionUID = -2124469847758108312L; 60: 61: /** Ascending order. */ 62: public static final SortOrder ASCENDING 63: = new SortOrder("SortOrder.ASCENDING"); 64: 65: /** Descending order. */ 66: public static final SortOrder DESCENDING 67: = new SortOrder("SortOrder.DESCENDING"); 68: 69: /** The name. */ 70: private String name; 71: 72: /** 73: * Private constructor. 74: * 75: * @param name the name. 76: */ 77: private SortOrder(final String name) { 78: this.name = name; 79: } 80: 81: /** 82: * Returns a string representing the object. 83: * 84: * @return The string. 85: */ 86: public String toString() { 87: return this.name; 88: } 89: 90: /** 91: * Returns <code>true</code> if this object is equal to the specified 92: * object, and <code>false</code> otherwise. 93: * 94: * @param obj the other object. 95: * 96: * @return A boolean. 97: */ 98: public boolean equals(final Object obj) { 99: 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: } 135: else if (this.equals(SortOrder.DESCENDING)) { 136: return SortOrder.DESCENDING; 137: } 138: return null; 139: } 140: }