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 */
017package org.apache.commons.configuration;
018
019import 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.html 901729 2014-03-15 20:24:09Z oheger $
031 */
032public 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}