/*
 * Copyright (C) 1999-2004 <a href="mailto:mandarax@jbdietrich.com">Jens Dietrich</a>
 *
 * 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 2 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 org.mandarax.kernel;

import java.util.*;

/**
 * Interface that can be extended/implemented by all interfaces/classes that want
 * to equip their respective instances with an additional parameter facility. 
 * Parameters are simple key-value pairs, both key and value are strings.
 * Implementations can use a java.util.Properties delegate.
 * @see java.util.Properties
 * @author <A HREF="mailto:mandarax@jbdietrich.com">Jens Dietrich</A>
 * @version 3.3.1 <9 August 2004>
 * @since 2.0
 */

public interface PropertiesSupport {
	
	/**
	 * Set a property.
	 * @param key the key
	 * @param value the value
	 * @return the previous value of the specified key in this property list, or null if it did not have one.
	 */
	Object setProperty(String key,String value);
	/**
	 * Get a property.
	 * @param key the property key
	 * @return the respective value. The method returns null if the property is not found. 
	 */
	String getProperty(String key);
	/**
	 * Remove a property.
	 * @param key the property key
	 * @return the value to which the key had been mapped, or null if the key did not have a mapping.
	 */
	Object removeProperty(String key);
	/** 
	 * Returns an enumeration of all the keys in this property list, including distinct 
	 * keys in the default property list if a key of the same name has not already been 
	 * found from the main properties list. 
	 * @return an enumeration of all the keys in this property list, including the keys in 
	 * the default property list
	 */
	Enumeration propertyNames();
	/**
	 * Get the properties as one "properties" instance.
	 * @return a properties instance
	 */
	Properties getProperties();
}
