org.jfree.util.ArrayUtilities Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jtstand-common Show documentation
jtstand-common is a library derived from jcommon, used by jtstand-chart, which is derived from jfreechart
There is a newer version: 1.5.9
/*
 * Copyright (c) 2009 Albert Kurucz. 
 *
 * This file, ArrayUtilities.java is part of JTStand.
 *
 * JTStand 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 3 of the License, or
 * (at your option) any later version.
 *
 * JTStand 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 GTStand.  If not, see .
 */

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;
    }

}