Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2014, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jfreechart/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. * * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. * Other names may be trademarks of their respective owners.] * * --------------- * ArrayUtils.java * --------------- * (C) Copyright 2003-2014, 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); * 16-Jun-2012 : Moved from JCommon to JFreeChart (DG); * */ package org.jfree.chart.util; import java.util.Arrays; /** * Utility methods for working with arrays. */ public class ArrayUtils { /** * Private constructor prevents object creation. */ private ArrayUtils() { } /** * Clones a two dimensional array of floats. * * @param array the array. * * @return A clone of the array. */ public static float[][] clone(float[][] array) { if (array == null) { return null; } float[][] result = new float[array.length][]; System.arraycopy(array, 0, result, 0, array.length); for (int i = 0; i < array.length; i++) { float[] child = array[i]; float[] copychild = new float[child.length]; System.arraycopy(child, 0, copychild, 0, child.length); result[i] = copychild; } return result; } /** * Returns <code>true</code> if all the references in <code>array1</code> * are equal to all the references in <code>array2</code> (two * <code>null</code> references are considered equal for this test). * * @param array1 the first array (<code>null</code> permitted). * @param array2 the second array (<code>null</code> permitted). * * @return A boolean. */ public static boolean equalReferencesInArrays(Object[] array1, 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 (<code>null</code> permitted). * @param array2 the second arrray (<code>null</code> permitted). * * @return A boolean. */ public static boolean equal(float[][] array1, 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 <code>true</code> if any two items in the array are equal to * one another. Any <code>null</code> values in the array are ignored. * * @param array the array to check. * * @return A boolean. */ public static boolean hasDuplicateItems(Object[] array) { for (int i = 0; i < array.length; i++) { for (int j = 0; j < i; j++) { Object o1 = array[i]; Object o2 = array[j]; if (o1 != null && o2 != null) { if (o1.equals(o2)) { return true; } } } } return false; } }