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 2014-2015 ForgeRock AS.
015 */
016
017package org.forgerock.util;
018
019/**
020 * A configuration option whose value can be stored in a set of {@link Options}.
021 * Refer to the appropriate class for the list of supported options.
022 *
023 * @param <T>
024 *            The type of value associated with the option.
025 */
026public final class Option<T> {
027    /**
028     * Defines an option with the provided type and default value.
029     *
030     * @param <T>
031     *            The type of value associated with the option.
032     * @param type
033     *            The type of value associated with the option.
034     * @param defaultValue
035     *            The default value for the option.
036     * @return An option with the provided type and default value.
037     */
038    public static <T> Option<T> of(final Class<T> type, final T defaultValue) {
039        return new Option<>(type, defaultValue);
040    }
041
042    /**
043     * Defines a boolean option with the provided default value.
044     *
045     * @param <T>
046     *            The type of value associated with the option.
047     * @param defaultValue
048     *            The default value for the option.
049     * @return A boolean option with the provided default value.
050     */
051    @SuppressWarnings("unchecked")
052    public static <T> Option<T> withDefault(final T defaultValue) {
053        return new Option<>((Class<T>) defaultValue.getClass(), defaultValue);
054    }
055
056    private final T defaultValue;
057    private final Class<T> type;
058
059    private Option(final Class<T> type, final T defaultValue) {
060        this.type = type;
061        this.defaultValue = defaultValue;
062    }
063
064    T getValue(final Object value) {
065        return value != null ? type.cast(value) : defaultValue;
066    }
067}