Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
/*
 * 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.
 */

import java.lang.reflect.Array;

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} followed
     * by all of the elements {@code array2}. 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 <T> the component type of the array
     * @param array1  the first array whose elements are added to the new array, may be {@code null}
     * @param array2  the second array whose elements are added to the new array, may be {@code null}
     * @return The new array, {@code null} if both arrays are {@code null}.
     *      The type of the new array is the type of the first array,
     *      unless the first array is null, in which case the type is the same as the second array.
     * @since 2.1
     * @throws IllegalArgumentException if the array types are incompatible
     */
    public static <T> T[] addAll(final T[] array1, final T... array2) {
        if (array1 == null) {
            return clone(array2);
        } else if (array2 == null) {
            return clone(array1);
        }
        final Class<?> type1 = array1.getClass().getComponentType();
        @SuppressWarnings("unchecked")
        // OK, because array is of type T
        final T[] joinedArray = (T[]) Array.newInstance(type1, array1.length + array2.length);
        System.arraycopy(array1, 0, joinedArray, 0, array1.length);
        try {
            System.arraycopy(array2, 0, joinedArray, array1.length, array2.length);
        } catch (final ArrayStoreException ase) {
            // Check if problem was due to incompatible types
            /*
             * We do this here, rather than before the copy because:
             * - it would be a wasted check most of the time
             * - safer, in case check turns out to be too strict
             */
            final Class<?> type2 = array2.getClass().getComponentType();
            if (!type1.isAssignableFrom(type2)) {
                throw new IllegalArgumentException(
                        "Cannot store " + type2.getName() + " in an array of " + type1.getName(), ase);
            }
            throw ase; // No, so rethrow original
        }
        return joinedArray;
    }

    /**
     * <p>Shallow clones an array returning a typecast result and handling
     * {@code null}.</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} for a {@code null} input array.</p>
     *
     * @param <T> the component type of the array
     * @param array  the array to shallow clone, may be {@code null}
     * @return the cloned array, {@code null} if {@code null} input
     */
    public static <T> T[] clone(final T[] array) {
        if (array == null) {
            return null;
        }
        return array.clone();
    }
}