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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  * ArrayUtilities.java
29  * -------------------
30  * (C) Copyright 2003-2005, by Object Refinery Limited.
31  *
32  * Original Author: David Gilbert (for Object Refinery Limited);
33  * Contributor(s): -;
34  *
35  * $Id: ArrayUtilities.java,v 1.6 2006/07/04 10:20:40 taqua Exp $
36  *
37  * Changes
38  * -------
39  * 21-Aug-2003 : Version 1 (DG);
40  * 04-Oct-2004 : Renamed ArrayUtils --> ArrayUtilities (DG);
41  *
42  */
43
44 package org.jfree.util;
45
46 import java.util.Arrays JavaDoc;
47
48 /**
49  * Utility methods for working with arrays.
50  *
51  * @author David Gilbert
52  */
53 public class ArrayUtilities {
54
55     /**
56      * Private constructor prevents object creation.
57      */
58     private ArrayUtilities() {
59     }
60
61     /**
62      * Clones a two dimensional array of floats.
63      *
64      * @param array the array.
65      *
66      * @return A clone of the array.
67      */
68     public static float[][] clone(final float[][] array) {
69     
70         if (array == null) {
71             return null;
72         }
73         final float[][] result = new float[array.length][];
74         System.arraycopy(array, 0, result, 0, array.length);
75
76         for (int i = 0; i < array.length; i++) {
77             final float[] child = array[i];
78             final float[] copychild = new float[child.length];
79             System.arraycopy(child, 0, copychild, 0, child.length);
80             result[i] = copychild;
81         }
82
83         return result;
84     
85     }
86     
87     /**
88      * Returns <code>true</code> if all the references in <code>array1</code>
89      * are equal to all the references in <code>array2</code> (two
90      * <code>null</code> references are considered equal for this test).
91      *
92      * @param array1 the first array (<code>null</code> permitted).
93      * @param array2 the second array (<code>null</code> permitted).
94      *
95      * @return A boolean.
96      */
97     public static boolean equalReferencesInArrays(final Object JavaDoc[] array1,
98                                                   final Object JavaDoc[] array2) {
99         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 JavaDoc[] array) {
165         for (int i = 0; i < array.length; i++) {
166             for (int j = 0; j < i; j++) {
167                 final Object JavaDoc o1 = array[i];
168                 final Object JavaDoc 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     public static int compareVersionArrays (Comparable JavaDoc[] a1, Comparable JavaDoc[] a2)
180     {
181       int length = Math.min (a1.length, a2.length);
182       for (int i = 0; i < length; i++)
183       {
184         Comparable JavaDoc o1 = a1[i];
185         Comparable JavaDoc o2 = a2[i];
186         if (o1 == null && o2 == null)
187         {
188           // cannot decide ..
189 continue;
190         }
191         if (o1 == null)
192         {
193           return 1;
194         }
195         if (o2 == null)
196         {
197            return -1;
198         }
199         int retval = o1.compareTo(o2);
200         if (retval != 0)
201         {
202           return retval;
203         }
204       }
205       return 0;
206     }
207
208 }
209
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