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.web.reactive.function;
018
019import java.util.List;
020import java.util.Map;
021import java.util.Optional;
022
023import org.springframework.http.ReactiveHttpInputMessage;
024import org.springframework.http.codec.HttpMessageReader;
025import org.springframework.http.server.reactive.ServerHttpResponse;
026
027/**
028 * A function that can extract data from a {@link ReactiveHttpInputMessage} body.
029 *
030 * @author Arjen Poutsma
031 * @since 5.0
032 * @param <T> the type of data to extract
033 * @param <M> the type of {@link ReactiveHttpInputMessage} this extractor can be applied to
034 * @see BodyExtractors
035 */
036@FunctionalInterface
037public interface BodyExtractor<T, M extends ReactiveHttpInputMessage> {
038
039        /**
040         * Extract from the given input message.
041         * @param inputMessage the request to extract from
042         * @param context the configuration to use
043         * @return the extracted data
044         */
045        T extract(M inputMessage, Context context);
046
047
048        /**
049         * Defines the context used during the extraction.
050         */
051        interface Context {
052
053                /**
054                 * Return the {@link HttpMessageReader HttpMessageReaders} to be used for body extraction.
055                 * @return the stream of message readers
056                 */
057                List<HttpMessageReader<?>> messageReaders();
058
059                /**
060                 * Optionally return the {@link ServerHttpResponse}, if present.
061                 */
062                Optional<ServerHttpResponse> serverResponse();
063
064                /**
065                 * Return the map of hints to use to customize body extraction.
066                 */
067                Map<String, Object> hints();
068        }
069
070}