/** Copyright 2004 The Apache Software Foundation** Licensed under the Apache License, Version 2.0 (the "License");* you may not use this file except in compliance with the License.* You may obtain a copy of the License at**     http://www.apache.org/licenses/LICENSE-2.0** Unless required by applicable law or agreed to in writing, software* distributed under the License is distributed on an "AS IS" BASIS,* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.* See the License for the specific language governing permissions and* limitations under the License.*/package javax.servlet;import java.util.EventListener;	/** Implementations of this interface receive notifications of	** changes to the attribute list on the servlet context of a web application. 	* To receive notification events, the implementation class	* must be configured in the deployment descriptor for the web application.	* @see ServletContextAttributeEvent	 * @since	v 2.3	*/public interface ServletContextAttributeListener extends EventListener {	/** Notification that a new attribute was added to the servlet context. Called after the attribute is added.*/public void attributeAdded(ServletContextAttributeEvent scab);	/** Notification that an existing attribute has been removed from the servlet context. Called after the attribute is removed.*/public void attributeRemoved(ServletContextAttributeEvent scab);	/** Notification that an attribute on the servlet context has been replaced. Called after the attribute is replaced. */public void attributeReplaced(ServletContextAttributeEvent scab);}