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
018package org.apache.commons.configuration.reloading;
019
020import org.apache.commons.configuration.FileConfiguration;
021import org.apache.commons.logging.Log;
022import org.apache.commons.logging.LogFactory;
023
024/**
025 * A strategy to reload configuration based on management requests. Designed for
026 * JMX management.
027 *
028 * @author Nicolas De loof
029 * @version $Id: ManagedReloadingStrategy.java 1210646 2011-12-05 21:25:01Z oheger $
030 */
031public class ManagedReloadingStrategy implements ReloadingStrategy,
032        ManagedReloadingStrategyMBean
033{
034    /** The logger. */
035    private Log log = LogFactory.getLog(ManagedReloadingStrategy.class);
036
037    /** Stores a reference to the associated configuration. */
038    private FileConfiguration configuration;
039
040    /** A flag whether a reload is required. */
041    private boolean reloadingRequired;
042
043    /**
044     * @see org.apache.commons.configuration.reloading.ReloadingStrategy#init()
045     */
046    public void init()
047    {
048    }
049
050    /**
051     * @see org.apache.commons.configuration.reloading.ReloadingStrategy#reloadingPerformed()
052     */
053    public void reloadingPerformed()
054    {
055        reloadingRequired = false;
056    }
057
058    /**
059     * Checks whether reloading is required. This implementation checks whether
060     * the {@code refresh()} method has been invoked.
061     *
062     * @return a flag whether reloading is required
063     * @see org.apache.commons.configuration.reloading.ReloadingStrategy#reloadingRequired()
064     */
065    public boolean reloadingRequired()
066    {
067        return reloadingRequired;
068    }
069
070    /**
071     * Sets the associated configuration.
072     *
073     * @param configuration the associated configuration
074     */
075    public void setConfiguration(FileConfiguration configuration)
076    {
077        this.configuration = configuration;
078    }
079
080    /**
081     * Tells this strategy that the monitored configuration file should be
082     * refreshed. This method will typically be called from outside (through an
083     * exposed MBean) on behalf of an administrator.
084     *
085     * @see org.apache.commons.configuration.reloading.ManagedReloadingStrategyMBean#refresh()
086     */
087    public void refresh()
088    {
089        log.info("Reloading configuration.");
090        this.reloadingRequired = true;
091        // force reloading
092        configuration.isEmpty();
093    }
094}