    001/* ========================================================================
    002 * JCommon : a free general purpose class library for the Java(tm) platform
    003 * ========================================================================
    004 *
    005 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
    006 *
    007 * Project Info:  http://www.jfree.org/jcommon/index.html
    008 *
    009 * This library is free software; you can redistribute it and/or modify it
    010 * under the terms of the GNU Lesser General Public License as published by
    011 * the Free Software Foundation; either version 2.1 of the License, or
    012 * (at your option) any later version.
    013 *
    014 * This library is distributed in the hope that it will be useful, but
    015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
    017 * License for more details.
    018 *
    019 * You should have received a copy of the GNU Lesser General Public
    020 * License along with this library; if not, write to the Free Software
    021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
    022 * USA.
    023 *
    024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
    025 * in the United States and other countries.]
    026 *
    027 * ------------------
    028 * Configuration.java
    029 * ------------------
    030 * (C)opyright 2002-2005, by Thomas Morgner and Contributors.
    031 *
    032 * Original Author:  Thomas Morgner (taquera@sherito.org);
    033 * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034 *
    035 * $Id: Configuration.java,v 1.8 2007/11/02 17:50:37 taqua Exp $
    036 *
    037 * Changes
    038 * -------
    039 * 02-May-2003 : Initial version (TM);
    040 *
    041 */
    042
    043package org.jfree.util;
    044
    045import java.io.Serializable;
    046import java.util.Enumeration;
    047import java.util.Iterator;
    048
    049/**
    050 * A simple query interface for a configuration.
    051 *
    052 * @author Thomas Morgner
    053 */
    054public interface Configuration extends Serializable, Cloneable {
    055
    056    /**
    057     * Returns the configuration property with the specified key.
    058     *
    059     * @param key  the property key.
    060     *
    061     * @return the property value.
    062     */
    063    public String getConfigProperty(String key);
    064
    065    /**
    066     * Returns the configuration property with the specified key (or the
    067     * specified default value if there is no such property).
    068     * <p>
    069     * If the property is not defined in this configuration, the code will
    070     * lookup the property in the parent configuration.
    071     *
    072     * @param key  the property key.
    073     * @param defaultValue  the default value.
    074     *
    075     * @return the property value.
    076     */
    077    public String getConfigProperty(String key, String defaultValue);
    078
    079    /**
    080     * Returns all keys with the given prefix.
    081     *
    082     * @param prefix the prefix
    083     * @return the iterator containing all keys with that prefix
    084     */
    085    public Iterator findPropertyKeys(String prefix);
    086
    087    /**
    088     * Returns the configuration properties.
    089     *
    090     * @return The configuration properties.
    091     */
    092    public Enumeration getConfigProperties();
    093
    094    /**
    095     * Returns a clone of the object.
    096     *
    097     * @return A clone.
    098     *
    099     * @throws CloneNotSupportedException if cloning is not supported for some reason.
    100     */
    101    public Object clone() throws CloneNotSupportedException;
    102
    103}