/*
* 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
*
* http://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.http.codec.multipart;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import org.springframework.core.ResolvableType;
import org.springframework.http.MediaType;
import org.springframework.http.ReactiveHttpInputMessage;
import org.springframework.http.codec.HttpMessageReader;
import org.springframework.util.Assert;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
/**
* {@code HttpMessageReader} for reading {@code "multipart/form-data"} requests
* into a {@code MultiValueMap<String, Part>}.
*
* <p>Note that this reader depends on access to an
* {@code HttpMessageReader<Part>} for the actual parsing of multipart content.
* The purpose of this reader is to collect the parts into a map.
*
* @author Rossen Stoyanchev
* @since 5.0
*/
public class MultipartHttpMessageReader implements HttpMessageReader<MultiValueMap<String, Part>> {
private static final ResolvableType MULTIPART_VALUE_TYPE = ResolvableType.forClassWithGenerics(
MultiValueMap.class, String.class, Part.class);
private final HttpMessageReader<Part> partReader;
public MultipartHttpMessageReader(HttpMessageReader<Part> partReader) {
Assert.notNull(partReader, "'partReader' is required");
this.partReader = partReader;
}
@Override
public List<MediaType> getReadableMediaTypes() {
return Collections.singletonList(MediaType.MULTIPART_FORM_DATA);
}
@Override
public boolean canRead(ResolvableType elementType, MediaType mediaType) {
return MULTIPART_VALUE_TYPE.isAssignableFrom(elementType) &&
(mediaType == null || MediaType.MULTIPART_FORM_DATA.isCompatibleWith(mediaType));
}
@Override
public Flux<MultiValueMap<String, Part>> read(ResolvableType elementType,
ReactiveHttpInputMessage message, Map<String, Object> hints) {
return Flux.from(readMono(elementType, message, hints));
}
@Override
public Mono<MultiValueMap<String, Part>> readMono(ResolvableType elementType,
ReactiveHttpInputMessage inputMessage, Map<String, Object> hints) {
return this.partReader.read(elementType, inputMessage, hints)
.collectMultimap(Part::name).map(this::toMultiValueMap);
}
private LinkedMultiValueMap<String, Part> toMultiValueMap(Map<String, Collection<Part>> map) {
return new LinkedMultiValueMap<>(map.entrySet().stream()
.collect(Collectors.toMap(Map.Entry::getKey, e -> toList(e.getValue()))));
}
private List<Part> toList(Collection<Part> collection) {
return collection instanceof List ? (List<Part>) collection : new ArrayList<>(collection);
}
}