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.accept;
018
019import java.util.Collections;
020import java.util.List;
021
022import org.springframework.http.MediaType;
023import org.springframework.web.HttpMediaTypeNotAcceptableException;
024import org.springframework.web.context.request.NativeWebRequest;
025
026/**
027 * A strategy for resolving the requested media types for a request.
028 *
029 * @author Rossen Stoyanchev
030 * @since 3.2
031 */
032@FunctionalInterface
033public interface ContentNegotiationStrategy {
034
035        /**
036         * A singleton list with {@link MediaType#ALL} that is returned from
037         * {@link #resolveMediaTypes} when no specific media types are requested.
038         * @since 5.0.5
039         */
040        List<MediaType> MEDIA_TYPE_ALL_LIST = Collections.singletonList(MediaType.ALL);
041
042
043        /**
044         * Resolve the given request to a list of media types. The returned list is
045         * ordered by specificity first and by quality parameter second.
046         * @param webRequest the current request
047         * @return the requested media types, or {@link #MEDIA_TYPE_ALL_LIST} if none
048         * were requested.
049         * @throws HttpMediaTypeNotAcceptableException if the requested media
050         * types cannot be parsed
051         */
052        List<MediaType> resolveMediaTypes(NativeWebRequest webRequest)
053                        throws HttpMediaTypeNotAcceptableException;
054
055}