Java tutorial
/* * 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 requests coming * into and going out of scope of a web application. * * <p>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 as 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>Implementations of this interface are invoked at their * {@link #requestInitialized} method in the order in which they have been * declared, and at their {@link #requestDestroyed} method in reverse * order. * * @since Servlet 2.4 */ public interface ServletRequestListener extends EventListener { /** * Receives notification that a ServletRequest is about to go out * of scope of the web application. * * @param sre the ServletRequestEvent containing the ServletRequest * and the ServletContext representing the web application * * @implSpec * The default implementation takes no action. */ default public void requestDestroyed(ServletRequestEvent sre) { } /** * Receives notification that a ServletRequest is about to come * into scope of the web application. * * @param sre the ServletRequestEvent containing the ServletRequest * and the ServletContext representing the web application * * @implSpec * The default implementation takes no action. */ default public void requestInitialized(ServletRequestEvent sre) { } }