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 * ArrayUtilities.java
029 * -------------------
030 * (C) Copyright 2003-2005, by Object Refinery Limited.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * $Id: ArrayUtilities.java,v 1.7 2008/09/10 09:21:30 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 21-Aug-2003 : Version 1 (DG);
040 * 04-Oct-2004 : Renamed ArrayUtils --> ArrayUtilities (DG);
041 *
042 */
043
044 package org.jfree.util;
045
046 import java.util.Arrays;
047
048 /**
049 * Utility methods for working with arrays.
050 *
051 * @author David Gilbert
052 */
053 public class ArrayUtilities {
054
055 /**
056 * Private constructor prevents object creation.
057 */
058 private ArrayUtilities() {
059 }
060
061 /**
062 * Clones a two dimensional array of floats.
063 *
064 * @param array the array.
065 *
066 * @return A clone of the array.
067 */
068 public static float[][] clone(final float[][] array) {
069
070 if (array == null) {
071 return null;
072 }
073 final float[][] result = new float[array.length][];
074 System.arraycopy(array, 0, result, 0, array.length);
075
076 for (int i = 0; i < array.length; i++) {
077 final float[] child = array[i];
078 final float[] copychild = new float[child.length];
079 System.arraycopy(child, 0, copychild, 0, child.length);
080 result[i] = copychild;
081 }
082
083 return result;
084
085 }
086
087 /**
088 * Returns <code>true</code> if all the references in <code>array1</code>
089 * are equal to all the references in <code>array2</code> (two
090 * <code>null</code> references are considered equal for this test).
091 *
092 * @param array1 the first array (<code>null</code> permitted).
093 * @param array2 the second array (<code>null</code> permitted).
094 *
095 * @return A boolean.
096 */
097 public static boolean equalReferencesInArrays(final Object[] array1,
098 final Object[] array2) {
099 if (array1 == null) {
100 return (array2 == null);
101 }
102 if (array2 == null) {
103 return false;
104 }
105 if (array1.length != array2.length) {
106 return false;
107 }
108 for (int i = 0; i < array1.length; i++) {
109 if (array1[i] == null) {
110 if (array2[i] != null) {
111 return false;
112 }
113 }
114 if (array2[i] == null) {
115 if (array1[i] != null) {
116 return false;
117 }
118 }
119 if (array1[i] != array2[i]) {
120 return false;
121 }
122 }
123 return true;
124 }
125
126 /**
127 * Tests two float arrays for equality.
128 *
129 * @param array1 the first array (<code>null</code> permitted).
130 * @param array2 the second arrray (<code>null</code> permitted).
131 *
132 * @return A boolean.
133 */
134 public static boolean equal(final float[][] array1,
135 final float[][] array2) {
136 if (array1 == null) {
137 return (array2 == null);
138 }
139
140 if (array2 == null) {
141 return false;
142 }
143
144 if (array1.length != array2.length) {
145 return false;
146 }
147
148 for (int i = 0; i < array1.length; i++) {
149 if (!Arrays.equals(array1[i], array2[i])) {
150 return false;
151 }
152 }
153 return true;
154 }
155
156 /**
157 * Returns <code>true</code> if any two items in the array are equal to
158 * one another. Any <code>null</code> values in the array are ignored.
159 *
160 * @param array the array to check.
161 *
162 * @return A boolean.
163 */
164 public static boolean hasDuplicateItems(final Object[] array) {
165 for (int i = 0; i < array.length; i++) {
166 for (int j = 0; j < i; j++) {
167 final Object o1 = array[i];
168 final Object o2 = array[j];
169 if (o1 != null && o2 != null) {
170 if (o1.equals(o2)) {
171 return true;
172 }
173 }
174 }
175 }
176 return false;
177 }
178
179 /**
180 * Compares the initial elements of two arrays.
181 *
182 * @param a1 array 1.
183 * @param a2 array 2.
184 *
185 * @return An integer showing the relative ordering.
186 */
187 public static int compareVersionArrays (Comparable[] a1, Comparable[] a2)
188 {
189 int length = Math.min (a1.length, a2.length);
190 for (int i = 0; i < length; i++)
191 {
192 Comparable o1 = a1[i];
193 Comparable o2 = a2[i];
194 if (o1 == null && o2 == null)
195 {
196 // cannot decide ..
197 continue;
198 }
199 if (o1 == null)
200 {
201 return 1;
202 }
203 if (o2 == null)
204 {
205 return -1;
206 }
207 int retval = o1.compareTo(o2);
208 if (retval != 0)
209 {
210 return retval;
211 }
212 }
213 return 0;
214 }
215
216 }