/*
 * Copyright 2002-2017 the original author or authors.
 *
 * 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
 *
 *      https://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 org.springframework.web.context.request;

Extends WebRequestInterceptor with a callback method invoked during asynchronous request handling. 
When a handler starts asynchronous request handling, the DispatcherServlet exits without invoking postHandle and afterCompletion, as it normally does, since the results of request handling (e.g. ModelAndView) are not available in the current thread and handling is not yet complete. In such scenarios, the afterConcurrentHandlingStarted(WebRequest) method is invoked instead allowing implementations to perform tasks such as cleaning up thread bound attributes. 
When asynchronous handling completes, the request is dispatched to the container for further processing. At this stage the DispatcherServlet invokes preHandle, postHandle and afterCompletion as usual. 
Author:
Rossen Stoyanchev
See Also:
WebAsyncManager
Since:
3.2/**
 * Extends {@code WebRequestInterceptor} with a callback method invoked during
 * asynchronous request handling.
 *
 * <p>When a handler starts asynchronous request handling, the DispatcherServlet
 * exits without invoking {@code postHandle} and {@code afterCompletion}, as it
 * normally does, since the results of request handling (e.g. ModelAndView) are
 * not available in the current thread and handling is not yet complete.
 * In such scenarios, the {@link #afterConcurrentHandlingStarted(WebRequest)}
 * method is invoked instead allowing implementations to perform tasks such as
 * cleaning up thread bound attributes.
 *
 * <p>When asynchronous handling completes, the request is dispatched to the
 * container for further processing. At this stage the DispatcherServlet invokes
 * {@code preHandle}, {@code postHandle} and {@code afterCompletion} as usual.
 *
 * @author Rossen Stoyanchev
 * @since 3.2
 *
 * @see org.springframework.web.context.request.async.WebAsyncManager
 */
public interface AsyncWebRequestInterceptor extends WebRequestInterceptor{

	
Called instead of postHandle and afterCompletion, when the handler started handling the request concurrently. 
Params:
request – the current request/**
	 * Called instead of {@code postHandle} and {@code afterCompletion}, when the
	 * handler started handling the request concurrently.
	 *
	 * @param request the current request
	 */
	void afterConcurrentHandlingStarted(WebRequest request);

}