001/*
002 * Copyright 2002-2015 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.servlet.mvc.method.annotation;
017
018
019import java.io.IOException;
020import java.io.OutputStream;
021
022/**
023 * A controller method return value type for asynchronous request processing
024 * where the application can write directly to the response {@code OutputStream}
025 * without holding up the Servlet container thread.
026 *
027 * <p><strong>Note:</strong> when using this option it is highly recommended to
028 * configure explicitly the TaskExecutor used in Spring MVC for executing
029 * asynchronous requests. Both the MVC Java config and the MVC namespaces provide
030 * options to configure asynchronous handling. If not using those, an application
031 * can set the {@code taskExecutor} property of
032 * {@link org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter
033 * RequestMappingHandlerAdapter}.
034 *
035 * @author Rossen Stoyanchev
036 * @since 4.2
037 */
038public interface StreamingResponseBody {
039
040        /**
041         * A callback for writing to the response body.
042         * @param outputStream the stream for the response body
043         * @throws IOException an exception while writing
044         */
045        void writeTo(OutputStream outputStream) throws IOException;
046
047}