001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *  http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    
020    //
021    // This source code implements specifications defined by the Java
022    // Community Process. In order to remain compliant with the specification
023    // DO NOT add / change / or delete method signatures!
024    //
025    
026    package javax.servlet;
027    
028    import java.util.EventListener;
029    
030    /**
031     * Implementations of this interface recieve notifications of
032     * changes to the attribute list on the servlet context of a web application.
033     * To recieve notification events, the implementation class
034     * must be configured in the deployment descriptor for the web application.
035     *
036     * @see ServletContextAttributeEvent
037     *
038     * @since Servlet 2.3
039     *
040     * @version $Rev: 467553 $ $Date: 2006-10-24 21:01:51 -0700 (Tue, 24 Oct 2006) $
041     */
042    public interface ServletContextAttributeListener extends EventListener {
043        /**
044         * Notification that a new attribute was added to the servlet context.
045         * Called after the attribute is added.
046         */
047        public void attributeAdded(ServletContextAttributeEvent scab);
048    
049        /**
050         * Notification that an existing attribute has been removed from the
051         * servlet context. Called after the attribute is removed.
052         */
053        public void attributeRemoved(ServletContextAttributeEvent scab);
054    
055        /**
056         * Notification that an attribute on the servlet context has been
057         * replaced. Called after the attribute is replaced.
058         */
059        public void attributeReplaced(ServletContextAttributeEvent scab);
060    }
061