geronimo-servlet_3.1_spec/src/main/java/javax/servlet/ServletContextAttributeListener.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 *
 * @version $Rev$ $Date$
 * @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.
     */
    void attributeAdded(ServletContextAttributeEvent scab);

    /**
     * Notification that an existing attribute has been removed from the servlet context. Called after the attribute is removed.
     */
    void attributeRemoved(ServletContextAttributeEvent scab);

    /**
     * Notification that an attribute on the servlet context has been replaced. Called after the attribute is replaced.
     */
    void attributeReplaced(ServletContextAttributeEvent scab);
}