|
/* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.lang.reflect.Array;
/**
* Operations on arrays, primitive arrays (like <code>int[]</code>) and
* primitive wrapper arrays (like <code>Integer[]</code>).
*
* This class tries to handle <code>null</code> input gracefully.
* An exception will not be thrown for a <code>null</code>
* array input. However, an Object array that contains a <code>null</code>
* element may throw an exception. Each method documents its behaviour.
*
* @author Stephen Colebourne
* @author Moritz Petersen
* @author <a href="mailto:fredrik@westermarck.com">Fredrik Westermarck</a>
* @author Nikolay Metchev
* @author Matthew Hawthorne
* @author Tim O'Brien
* @author Pete Gieser
* @author Gary Gregory
* @author <a href="mailto:equinus100@hotmail.com">Ashwin S</a>
* @author Maarten Coene
* @since 2.0
* @version $Id: ArrayUtils.java 632503 2008-03-01 00:21:52Z ggregory $
*/
public class Main {
/**
* Finds the last index of the given object in the array starting at the given index.
*
* This method returns {@link #INDEX_NOT_FOUND} (<code>-1</code>) for a <code>null</code> input array.
*
* A negative startIndex will return {@link #INDEX_NOT_FOUND} (<code>-1</code>). A startIndex larger than
* the array length will search from the end of the array.
*
* @param array the array to traverse for looking for the object, may be <code>null</code>
* @param objectToFind the object to find, may be <code>null</code>
* @param startIndex the start index to travers backwards from
* @return the last index of the object within the array,
* {@link #INDEX_NOT_FOUND} (<code>-1</code>) if not found or <code>null</code> array input
*/
public static int lastIndexOf(Object[] array, Object objectToFind, int startIndex) {
if (array == null) {
return -1;
}
if (startIndex < 0) {
return -1;
} else if (startIndex >= array.length) {
startIndex = array.length - 1;
}
if (objectToFind == null) {
for (int i = startIndex; i >= 0; i--) {
if (array[i] == null) {
return i;
}
}
} else {
for (int i = startIndex; i >= 0; i--) {
if (objectToFind.equals(array[i])) {
return i;
}
}
}
return -1;
}
}
|