Java tutorial
import java.lang.reflect.Array; /* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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. * * */ /** * @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 { // Subarrays //----------------------------------------------------------------------- /** * Produces a new array containing the elements between * the start and end indices. * * The start index is inclusive, the end index exclusive. * Null array input produces null output. * * The component type of the subarray is always the same as * that of the input array. Thus, if the input is an array of type * <code>Date</code>, the following usage is envisaged: * * <pre> * Date[] someDates = (Date[])ArrayUtils.subarray(allDates, 2, 5); * </pre> * * @param array the array * @param startIndexInclusive the starting index. Undervalue (<0) * is promoted to 0, overvalue (>array.length) results * in an empty array. * @param endIndexExclusive elements up to endIndex-1 are present in the * returned subarray. Undervalue (< startIndex) produces * empty array, overvalue (>array.length) is demoted to * array length. * @return a new array containing the elements between * the start and end indices. * @since 2.1 */ public static Object[] subarray(Object[] array, int startIndexInclusive, int endIndexExclusive) { if (array == null) { return null; } if (startIndexInclusive < 0) { startIndexInclusive = 0; } if (endIndexExclusive > array.length) { endIndexExclusive = array.length; } int newSize = endIndexExclusive - startIndexInclusive; Class type = array.getClass().getComponentType(); if (newSize <= 0) { return (Object[]) Array.newInstance(type, 0); } Object[] subarray = (Object[]) Array.newInstance(type, newSize); System.arraycopy(array, startIndexInclusive, subarray, 0, newSize); return subarray; } }