/* * 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.reactive.accept; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import org.springframework.http.MediaType; import org.springframework.http.MediaTypeFactory; import org.springframework.util.Assert; import org.springframework.util.StringUtils; import org.springframework.web.server.NotAcceptableStatusException; import org.springframework.web.server.ServerWebExchange; /** * Resolver that checks a query parameter and uses it to lookup a matching * MediaType. Lookup keys can be registered or as a fallback * {@link MediaTypeFactory} can be used to perform a lookup. * * @author Rossen Stoyanchev * @since 5.0 */ public class ParameterContentTypeResolver implements RequestedContentTypeResolver { /** Primary lookup for media types by key (e.g. "json" -> "application/json") */ private final Map<String, MediaType> mediaTypes = new ConcurrentHashMap<>(64); private String parameterName = "format"; public ParameterContentTypeResolver(Map<String, MediaType> mediaTypes) { mediaTypes.forEach((key, value) -> this.mediaTypes.put(formatKey(key), value)); } private static String formatKey(String key) { return key.toLowerCase(Locale.ENGLISH); } /** * Set the name of the parameter to use to determine requested media types. * <p>By default this is set to {@literal "format"}. */ public void setParameterName(String parameterName) { Assert.notNull(parameterName, "'parameterName' is required"); this.parameterName = parameterName; } public String getParameterName() { return this.parameterName; } @Override public List<MediaType> resolveMediaTypes(ServerWebExchange exchange) throws NotAcceptableStatusException { String key = exchange.getRequest().getQueryParams().getFirst(getParameterName()); if (!StringUtils.hasText(key)) { return MEDIA_TYPE_ALL_LIST; } key = formatKey(key); MediaType match = this.mediaTypes.get(key); if (match == null) { match = MediaTypeFactory.getMediaType("filename." + key) .orElseThrow(() -> { List<MediaType> supported = new ArrayList<>(this.mediaTypes.values()); return new NotAcceptableStatusException(supported); }); } this.mediaTypes.putIfAbsent(key, match); return Collections.singletonList(match); } }