001/*
002 * Copyright 2002-2012 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.springframework.web.context.request;
017
018/**
019 * Extends {@code WebRequestInterceptor} with a callback method invoked during
020 * asynchronous request handling.
021 *
022 * <p>When a handler starts asynchronous request handling, the DispatcherServlet
023 * exits without invoking {@code postHandle} and {@code afterCompletion}, as it
024 * normally does, since the results of request handling (e.g. ModelAndView) are
025 * not available in the current thread and handling is not yet complete.
026 * In such scenarios, the {@link #afterConcurrentHandlingStarted(WebRequest)}
027 * method is invoked instead allowing implementations to perform tasks such as
028 * cleaning up thread bound attributes.
029 *
030 * <p>When asynchronous handling completes, the request is dispatched to the
031 * container for further processing. At this stage the DispatcherServlet invokes
032 * {@code preHandle}, {@code postHandle} and {@code afterCompletion} as usual.
033 *
034 * @author Rossen Stoyanchev
035 * @since 3.2
036 *
037 * @see org.springframework.web.context.request.async.WebAsyncManager
038 */
039public interface AsyncWebRequestInterceptor extends WebRequestInterceptor{
040
041        /**
042         * Called instead of {@code postHandle} and {@code afterCompletion}, when the
043         * the handler started handling the request concurrently.
044         *
045         * @param request the current request
046         */
047        void afterConcurrentHandlingStarted(WebRequest request);
048
049}