/*
 * 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;

    /**
     * A ServletRequestAttributeListener can be implemented by the
     * developer interested in being notified of request attribute
     * changes. Notifications will be generated while the request
     * is within the scope of the web application in which the listener
     * is registered. A request is defined as coming into scope when
     * it is about to enter the first servlet or filter in each web
     * application, as going out of scope when it exits the last servlet
     * or the first filter in the chain.
     *
     * @since Servlet 2.4
     */

public interface ServletRequestAttributeListener extends EventListener {
    /** Notification that a new attribute was added to the
     ** servlet request. Called after the attribute is added.
     */
    public void attributeAdded(ServletRequestAttributeEvent srae);

    /** Notification that an existing attribute has been removed from the
     ** servlet request. Called after the attribute is removed.
     */
    public void attributeRemoved(ServletRequestAttributeEvent srae);

    /** Notification that an attribute was replaced on the
     ** servlet request. Called after the attribute is replaced.
     */
    public void attributeReplaced(ServletRequestAttributeEvent srae);
}

