/* 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 int[]) and
* primitive wrapper arrays (like Integer[]).
*
* This class tries to handle null input gracefully.
* An exception will not be thrown for a null
* array input. However, an Object array that contains a null
* element may throw an exception. Each method documents its behaviour.
*
* @author Stephen Colebourne
* @author Moritz Petersen
* @author Fredrik Westermarck
* @author Nikolay Metchev
* @author Matthew Hawthorne
* @author Tim O'Brien
* @author Pete Gieser
* @author Gary Gregory
* @author Ashwin S
* @author Maarten Coene
* @since 2.0
* @version $Id: ArrayUtils.java 632503 2008-03-01 00:21:52Z ggregory $
*/
public class Main {
/**
* Inserts the specified element at the specified position in the array.
* Shifts the element currently at that position (if any) and any subsequent
* elements to the right (adds one to their indices).
*
* This method returns a new array with the same elements of the input
* array plus the given element on the specified position. The component
* type of the returned array is always the same as that of the input
* array.
*
* If the input array is null, a new one element array is returned
* whose component type is the same as the element.
*
*
* ArrayUtils.add([1], 0, 2) = [2, 1]
* ArrayUtils.add([2, 6], 2, 10) = [2, 6, 10]
* ArrayUtils.add([2, 6], 0, -4) = [-4, 2, 6]
* ArrayUtils.add([2, 6, 3], 2, 1) = [2, 6, 1, 3]
*
*
* @param array the array to add the element to, may be null
* @param index the position of the new object
* @param element the object to add
* @return A new array containing the existing elements and the new element
* @throws IndexOutOfBoundsException if the index is out of range
* (index < 0 || index > array.length).
*/
public static short[] add(short[] array, int index, short element) {
return (short[]) add(array, index, new Short(element), Short.TYPE);
}
/**
* Underlying implementation of add(array, index, element) methods.
* The last parameter is the class, which may not equal element.getClass
* for primitives.
*
* @param array the array to add the element to, may be null
* @param index the position of the new object
* @param element the object to add
* @param clss the type of the element being added
* @return A new array containing the existing elements and the new element
*/
private static Object add(Object array, int index, Object element, Class clss) {
if (array == null) {
if (index != 0) {
throw new IndexOutOfBoundsException("Index: " + index + ", Length: 0");
}
Object joinedArray = Array.newInstance(clss, 1);
Array.set(joinedArray, 0, element);
return joinedArray;
}
int length = Array.getLength(array);
if (index > length || index < 0) {
throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + length);
}
Object result = Array.newInstance(clss, length + 1);
System.arraycopy(array, 0, result, 0, index);
Array.set(result, index, element);
if (index < length) {
System.arraycopy(array, index, result, index + 1, length - index);
}
return result;
}
}