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/* 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;
/**
* <p>Operations on arrays, primitive arrays (like <code>int[]</code>) and
* primitive wrapper arrays (like <code>Integer[]</code>).</p>
*
* <p>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.</p>
*
* @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 {
/**
* <p>Adds all the elements of the given arrays into a new array.</p>
* <p>The new array contains all of the element of <code>array1</code> followed
* by all of the elements <code>array2</code>. When an array is returned, it is always
* a new array.</p>
*
* <pre>
* ArrayUtils.addAll(null, null) = null
* ArrayUtils.addAll(array1, null) = cloned copy of array1
* ArrayUtils.addAll(null, array2) = cloned copy of array2
* ArrayUtils.addAll([], []) = []
* ArrayUtils.addAll([null], [null]) = [null, null]
* ArrayUtils.addAll(["a", "b", "c"], ["1", "2", "3"]) = ["a", "b", "c", "1", "2", "3"]
* </pre>
*
* @param array1 the first array whose elements are added to the new array, may be <code>null</code>
* @param array2 the second array whose elements are added to the new array, may be <code>null</code>
* @return The new array, <code>null</code> if <code>null</code> array inputs.
* The type of the new array is the type of the first array.
* @since 2.1
*/
public static Object[] addAll(Object[] array1, Object[] array2) {
if (array1 == null) {
return clone(array2);
} else if (array2 == null) {
return clone(array1);
}
Object[] joinedArray = (Object[]) Array.newInstance(array1.getClass().getComponentType(),
array1.length + array2.length);
System.arraycopy(array1, 0, joinedArray, 0, array1.length);
System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
return joinedArray;
}
/**
* <p>Shallow clones an array returning a typecast result and handling
* <code>null</code>.</p>
*
* <p>The objects in the array are not cloned, thus there is no special
* handling for multi-dimensional arrays.</p>
*
* <p>This method returns <code>null</code> for a <code>null</code> input array.</p>
*
* @param array the array to shallow clone, may be <code>null</code>
* @return the cloned array, <code>null</code> if <code>null</code> input
*/
public static Object[] clone(Object[] array) {
if (array == null) {
return null;
}
return (Object[]) array.clone();
}
}
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