hu.netmind.beankeeper.config.impl.ConfigurationTrackerImpl.java Source code

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Here is the source code for hu.netmind.beankeeper.config.impl.ConfigurationTrackerImpl.java

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/**
 * Copyright (C) 2008 NetMind Consulting Bt.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package hu.netmind.beankeeper.config.impl;

import hu.netmind.beankeeper.config.ConfigurationTracker;
import hu.netmind.beankeeper.config.ExtendedConfigurationListener;
import hu.netmind.beankeeper.common.StoreException;
import org.apache.commons.configuration.AbstractConfiguration;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.event.ConfigurationListener;
import org.apache.commons.configuration.PropertiesConfiguration;
import java.util.*;

/**
 * Configuration can be queried and altered through this tracker.
 * @author Brautigam Robert
 * @version Revision: $Revision$
 */
public class ConfigurationTrackerImpl implements ConfigurationTracker {
    private AbstractConfiguration configuration = null;
    private List listeners = new ArrayList();

    public void init(Map parameters) {
        try {
            // Initialize with property reader configuration
            setConfiguration(new PropertiesConfiguration("beankeeper.properties"));
        } catch (Exception e) {
            throw new StoreException("fatal error, could not load default configuration", e);
        }
    }

    public void release() {
    }

    public Configuration getConfiguration() {
        return configuration;
    }

    /**
     * Set a new configuration for beankeeper. If you set a new configuration
     * object, all values will be re-read on the fly.
     */
    public void setConfiguration(AbstractConfiguration configuration) {
        if (configuration == null)
            return;
        // First clear all listeners from previous configuration if
        // there was one
        if (this.configuration != null) {
            Iterator listenersIterator = listeners.iterator();
            while (listenersIterator.hasNext())
                this.configuration.removeConfigurationListener((ConfigurationListener) listenersIterator.next());
        }
        // Set new configuration
        this.configuration = configuration;
        // Set all listeners, and invoke reload on all
        Iterator listenersIterator = listeners.iterator();
        while (listenersIterator.hasNext()) {
            ExtendedConfigurationListener listener = (ExtendedConfigurationListener) listenersIterator.next();
            this.configuration.addConfigurationListener(listener);
            listener.configurationReload();
        }
    }

    /**
     * Add a listener to the configuration tracker.
     */
    public void addListener(ExtendedConfigurationListener listener) {
        // Add to our internal listener list
        listeners.add(listener);
        // Add to current configuration
        configuration.addConfigurationListener(listener);
    }

    /**
     * Remove a listener from the configuration tracker.
     */
    public void removeListener(ExtendedConfigurationListener listener) {
        // Remove from our internal listener list
        listeners.remove(listener);
        // Remove from current configuration
        configuration.removeConfigurationListener(listener);
    }
}