    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *     http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017    package org.apache.commons.configuration;
    018
    019    import org.apache.commons.configuration.reloading.Reloadable;
    020
    021    /**
    022     * <p>A base class for hierarchical configurations with specific reloading
    023     * requirements.</p>
    024     * <p>This class manages a lock object which can be used for synchronization.</p>
    025     *
    026     * @author <a
    027     *         href="http://commons.apache.org/configuration/team-list.html">Commons
    028     *         Configuration team</a>
    029     * @since 1.7
    030     * @version $Id: HierarchicalReloadableConfiguration.java 1210000 2011-12-03 20:43:38Z oheger $
    031     */
    032    public class HierarchicalReloadableConfiguration extends HierarchicalConfiguration
    033        implements Reloadable
    034    {
    035        /** Constant for the name used for the lock object. */
    036        private static final String LOCK_NAME = "HierarchicalReloadableConfigurationLock";
    037
    038        /** The lock object used by this instance. */
    039        private final Object reloadLock;
    040
    041        /**
    042         * Creates a new instance of {@code HierarchicalReloadableConfiguration}.
    043         */
    044        public HierarchicalReloadableConfiguration()
    045        {
    046            super();
    047            reloadLock = new Lock(LOCK_NAME);
    048        }
    049
    050        /**
    051         * Creates a new instance of {@code HierarchicalReloadableConfiguration} and
    052         * initializes it with the given lock object.
    053         *
    054         * @param lock the lock object
    055         */
    056        public HierarchicalReloadableConfiguration(Object lock)
    057        {
    058            super();
    059            reloadLock = lock == null ? new Lock(LOCK_NAME) : lock;
    060        }
    061
    062        /**
    063         * Creates a new instance of {@code HierarchicalReloadableConfiguration} and
    064         * copies all data contained in the specified configuration into the new
    065         * one.
    066         *
    067         * @param c the configuration that is to be copied (if <b>null</b>, this
    068         * constructor will behave like the standard constructor)
    069         */
    070        public HierarchicalReloadableConfiguration(HierarchicalConfiguration c)
    071        {
    072            super(c);
    073            reloadLock = new Lock(LOCK_NAME);
    074        }
    075
    076        @Override
    077        public Object getReloadLock()
    078        {
    079            return reloadLock;
    080        }
    081    }