Copies the given array and adds the given element at the end of the new array. (long value type) : Array Copy Clone « Collections « Java Tutorial

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3. Array Copy Clone

/*   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>Copies the given array and adds the given element at the end of the new array.</p>
   *
   * <p>The new array contains the same elements of the input
   * array plus the given element in the last position. The component type of 
   * the new array is the same as that of the input array.</p>
   *
   * <p>If the input array is <code>null</code>, a new one element array is returned
   *  whose component type is the same as the element.</p>
   * 
   * <pre>
   * ArrayUtils.add(null, 0)   = [0]
   * ArrayUtils.add([1], 0)    = [1, 0]
   * ArrayUtils.add([1, 0], 1) = [1, 0, 1]
   * </pre>
   * 
   * @param array  the array to copy and add the element to, may be <code>null</code>
   * @param element  the object to add at the last index of the new array
   * @return A new array containing the existing elements plus the new element
   * @since 2.1
   */
  public static long[] add(long[] array, long element) {
      long[] newArray = (long[])copyArrayGrow1(array, Long.TYPE);
      newArray[newArray.length - 1] = element;
      return newArray;
  }

  
  /**
   * Returns a copy of the given array of size 1 greater than the argument. 
   * The last value of the array is left to the default value.
   * 
   * @param array The array to copy, must not be <code>null</code>.
   * @param newArrayComponentType If <code>array</code> is <code>null</code>, create a 
   * size 1 array of this type.
   * @return A new copy of the array of size 1 greater than the input.
   */    
  private static Object copyArrayGrow1(Object array, Class newArrayComponentType) {
      if (array != null) {
          int arrayLength = Array.getLength(array);
          Object newArray = Array.newInstance(array.getClass().getComponentType(), arrayLength + 1);
          System.arraycopy(array, 0, newArray, 0, arrayLength);
          return newArray;
      }
      return Array.newInstance(newArrayComponentType, 1);
  }


}