servletapi/jsr154/src/share/javax/servlet/ServletRequestAttributeListener.java

/*
* 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;

    /**
     * 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);
}