001/*
002 * The contents of this file are subject to the terms of the Common Development and
003 * Distribution License (the License). You may not use this file except in compliance with the
004 * License.
005 *
006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
007 * specific language governing permission and limitations under the License.
008 *
009 * When distributing Covered Software, include this CDDL Header Notice in each file and include
010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
011 * Header, with the fields enclosed by brackets [] replaced by your own identifying
012 * information: "Portions Copyright [year] [name of copyright owner]".
013 *
014 * Copyright 2015 ForgeRock AS.
015 */
016
017package org.forgerock.http.util;
018
019import java.util.List;
020
021/**
022 * Provides helper methods for {@link List}.
023 */
024public final class Lists {
025
026    private Lists() { }
027
028    /**
029     * Returns the given list content as an array, or {@code null} if the list is empty.
030     *
031     * @param listOfStrings
032     *         list to be converted
033     * @return the given list content as an array, or {@code null} if the list is empty.
034     */
035    public static String[] asArrayOrNull(final List<String> listOfStrings) {
036        if (listOfStrings.isEmpty()) {
037            return null;
038        }
039        return listOfStrings.toArray(new String[listOfStrings.size()]);
040    }
041
042}