001/*
002 * Copyright 2002-2018 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 */
016
017package org.springframework.http;
018
019import java.io.IOException;
020import java.io.OutputStream;
021
022/**
023 * Represents a HTTP output message that allows for setting a streaming body.
024 * Note that such messages typically do not support {@link #getBody()} access.
025 *
026 * @author Arjen Poutsma
027 * @since 4.0
028 * @see #setBody
029 */
030public interface StreamingHttpOutputMessage extends HttpOutputMessage {
031
032        /**
033         * Set the streaming body callback for this message.
034         * @param body the streaming body callback
035         */
036        void setBody(Body body);
037
038
039        /**
040         * Defines the contract for bodies that can be written directly to an
041         * {@link OutputStream}. Useful with HTTP client libraries that provide
042         * indirect access to an {@link OutputStream} via a callback mechanism.
043         */
044        interface Body {
045
046                /**
047                 * Write this body to the given {@link OutputStream}.
048                 * @param outputStream the output stream to write to
049                 * @throws IOException in case of I/O errors
050                 */
051                void writeTo(OutputStream outputStream) throws IOException;
052        }
053
054}