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JCommon is a free general purpose Java class library that is used in several projects at www.jfree.org, including JFreeChart and JFreeReport.
/* ========================================================================
* 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.]
*
* -------------------
* ArrayUtilities.java
* -------------------
* (C) Copyright 2003-2005, by Object Refinery Limited.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* $Id: ArrayUtilities.java,v 1.7 2008/09/10 09:21:30 mungady Exp $
*
* Changes
* -------
* 21-Aug-2003 : Version 1 (DG);
* 04-Oct-2004 : Renamed ArrayUtils --> ArrayUtilities (DG);
*
*/
package org.jfree.util;
import java.util.Arrays;
/**
* Utility methods for working with arrays.
*
* @author David Gilbert
*/
public class ArrayUtilities {
/**
* Private constructor prevents object creation.
*/
private ArrayUtilities() {
}
/**
* Clones a two dimensional array of floats.
*
* @param array the array.
*
* @return A clone of the array.
*/
public static float[][] clone(final float[][] array) {
if (array == null) {
return null;
}
final float[][] result = new float[array.length][];
System.arraycopy(array, 0, result, 0, array.length);
for (int i = 0; i < array.length; i++) {
final float[] child = array[i];
final float[] copychild = new float[child.length];
System.arraycopy(child, 0, copychild, 0, child.length);
result[i] = copychild;
}
return result;
}
/**
* Returns true if all the references in array1
* are equal to all the references in array2 (two
* null references are considered equal for this test).
*
* @param array1 the first array (null permitted).
* @param array2 the second array (null permitted).
*
* @return A boolean.
*/
public static boolean equalReferencesInArrays(final Object[] array1,
final Object[] array2) {
if (array1 == null) {
return (array2 == null);
}
if (array2 == null) {
return false;
}
if (array1.length != array2.length) {
return false;
}
for (int i = 0; i < array1.length; i++) {
if (array1[i] == null) {
if (array2[i] != null) {
return false;
}
}
if (array2[i] == null) {
if (array1[i] != null) {
return false;
}
}
if (array1[i] != array2[i]) {
return false;
}
}
return true;
}
/**
* Tests two float arrays for equality.
*
* @param array1 the first array (null permitted).
* @param array2 the second arrray (null permitted).
*
* @return A boolean.
*/
public static boolean equal(final float[][] array1,
final float[][] array2) {
if (array1 == null) {
return (array2 == null);
}
if (array2 == null) {
return false;
}
if (array1.length != array2.length) {
return false;
}
for (int i = 0; i < array1.length; i++) {
if (!Arrays.equals(array1[i], array2[i])) {
return false;
}
}
return true;
}
/**
* Returns true if any two items in the array are equal to
* one another. Any null values in the array are ignored.
*
* @param array the array to check.
*
* @return A boolean.
*/
public static boolean hasDuplicateItems(final Object[] array) {
for (int i = 0; i < array.length; i++) {
for (int j = 0; j < i; j++) {
final Object o1 = array[i];
final Object o2 = array[j];
if (o1 != null && o2 != null) {
if (o1.equals(o2)) {
return true;
}
}
}
}
return false;
}
/**
* Compares the initial elements of two arrays.
*
* @param a1 array 1.
* @param a2 array 2.
*
* @return An integer showing the relative ordering.
*/
public static int compareVersionArrays (Comparable[] a1, Comparable[] a2)
{
int length = Math.min (a1.length, a2.length);
for (int i = 0; i < length; i++)
{
Comparable o1 = a1[i];
Comparable o2 = a2[i];
if (o1 == null && o2 == null)
{
// cannot decide ..
continue;
}
if (o1 == null)
{
return 1;
}
if (o2 == null)
{
return -1;
}
int retval = o1.compareTo(o2);
if (retval != 0)
{
return retval;
}
}
return 0;
}
}