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/* * Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved. * 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; /** * Interface for receiving notification events about ServletRequest * attribute changes. * * <p>Notifications will be generated while the request * is within the scope of the web application. A ServletRequest * is defined as coming into scope of a web application when it * is about to enter the first servlet or filter of the web * application, and as going out of scope when it exits the last * servlet or the first filter in the chain. * * <p>In order to receive these notification events, the implementation * class must be either declared in the deployment descriptor of the web * application, annotated with {@link javax.servlet.annotation.WebListener}, * or registered via one of the addListener methods defined on * {@link ServletContext}. * * <p>The order in which implementations of this interface are invoked is * unspecified. * * @since Servlet 2.4 */ public interface ServletRequestAttributeListener extends EventListener { /** * Receives notification that an attribute has been added to the * ServletRequest. * * @param srae the ServletRequestAttributeEvent containing the * ServletRequest and the name and value of the attribute that was * added * * @implSpec * The default implementation takes no action. */ default public void attributeAdded(ServletRequestAttributeEvent srae) { } /** * Receives notification that an attribute has been removed from the * ServletRequest. * * @param srae the ServletRequestAttributeEvent containing the * ServletRequest and the name and value of the attribute that was * removed * * @implSpec * The default implementation takes no action. */ default public void attributeRemoved(ServletRequestAttributeEvent srae) { } /** * Receives notification that an attribute has been replaced on the * ServletRequest. * * @param srae the ServletRequestAttributeEvent containing the * ServletRequest and the name and (old) value of the attribute * that was replaced * * @implSpec * The default implementation takes no action. */ default public void attributeReplaced(ServletRequestAttributeEvent srae) { } }