source: trunk/java-utils/src/main/java/de/ugoe/cs/util/ArrayTools.java @ 620

package de.ugoe.cs.util;

/**
 * <p>
 * Helper class that provides methods to simplify working with arrays.
 * </p>
 * 
 * @author Steffen Herbold
 * @version 1.0
 */
final public class ArrayTools {

        /**
         * <p>
         * Private constructor to prevent initializing of the class.
         * </p>
         */
        private ArrayTools() {

        }

        /**
         * <p>
         * Finds the first occurrence of an object inside an array.
         * </p>
         * <p>
         * In case {@code other==null}, the first occurrence of a {@code null} value
         * in the array is returned.
         * </p>
         * 
         * @param array
         *            the array
         * @param other
         *            the object
         * @return index of the object if found, -1 otherwise
         */
        public static int findIndex(Object[] array, Object other) {
                int retVal = -1;
                for (int i = 0; i < array.length && retVal == -1; i++) {
                        if (other != null) {
                                if (array[i] != null && array[i].equals(other)) {
                                        retVal = i;
                                }
                        } else {
                                if (array[i] == null) {
                                        retVal = i;
                                }
                        }
                }
                return retVal;
        }

        /**
         * <p>
         * Finds the highest element in an array. If multiple elements have the
         * maximum value, the index of the first one is returned; null-values are
         * ignored. In case the parameter array is null, has length 0 or contains
         * only null-values, -1 is returned.
         * </p>
         * 
         * @param <T>
         * @param array
         *            the array
         * @return index of the element with the highest value, -1 in case of an
         *         invalid parameter
         */
        @SuppressWarnings("unchecked")
        public static <T> int findMax(Comparable<T>[] array) {
                int maxIndex = -1;
                T maxElement = null;
                if (array != null) {
                        for (int i = 0; i < array.length; i++) {
                                if (array[i] != null) {
                                        if (maxElement == null
                                                        || array[i].compareTo(maxElement) > 0) {
                                                maxElement = (T) array[i];
                                                maxIndex = i;
                                        }
                                }
                        }
                }
                return maxIndex;
        }

        /**
         * <p>
         * Finds the lowest element in an array. If multiple elements have the
         * minimal value, the index of the first one is returned; null-values are
         * ignored. In case the parameter array is null, has length 0 or contains
         * only null-values, -1 is returned.
         * </p>
         * 
         * @param <T>
         * @param array
         *            the array
         * @return index of the element with the lowest value, -1 in case of an
         *         invalid parameter
         */
        @SuppressWarnings("unchecked")
        public static <T> int findMin(Comparable<T>[] array) {
                int maxIndex = -1;
                T maxElement = null;
                if (array != null) {
                        for (int i = 0; i < array.length; i++) {
                                if (array[i] != null) {
                                        if (maxElement == null
                                                        || array[i].compareTo(maxElement) < 0) {
                                                maxElement = (T) array[i];
                                                maxIndex = i;
                                        }
                                }
                        }
                }
                return maxIndex;
        }
}