/*
* 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.core.codec;
import java.io.ByteArrayInputStream;
import java.util.Map;
import org.reactivestreams.Publisher;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import org.springframework.core.ResolvableType;
import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.InputStreamResource;
import org.springframework.core.io.Resource;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.util.MimeType;
import org.springframework.util.MimeTypeUtils;
/**
* Decoder for {@link Resource}s.
*
* @author Arjen Poutsma
* @since 5.0
*/
public class ResourceDecoder extends AbstractDecoder<Resource> {
public ResourceDecoder() {
super(MimeTypeUtils.ALL);
}
@Override
public boolean canDecode(ResolvableType elementType, MimeType mimeType) {
Class<?> clazz = elementType.getRawClass();
return (InputStreamResource.class.equals(clazz) ||
clazz.isAssignableFrom(ByteArrayResource.class)) &&
super.canDecode(elementType, mimeType);
}
@Override
public Flux<Resource> decode(Publisher<DataBuffer> inputStream, ResolvableType elementType,
MimeType mimeType, Map<String, Object> hints) {
return Flux.from(decodeToMono(inputStream, elementType, mimeType, hints));
}
@Override
public Mono<Resource> decodeToMono(Publisher<DataBuffer> inputStream, ResolvableType elementType,
MimeType mimeType, Map<String, Object> hints) {
Class<?> clazz = elementType.getRawClass();
Mono<byte[]> byteArray = Flux.from(inputStream).
reduce(DataBuffer::write).
map(dataBuffer -> {
byte[] bytes = new byte[dataBuffer.readableByteCount()];
dataBuffer.read(bytes);
DataBufferUtils.release(dataBuffer);
return bytes;
});
if (InputStreamResource.class.equals(clazz)) {
return Mono.from(byteArray.map(ByteArrayInputStream::new).map(InputStreamResource::new));
}
else if (clazz.isAssignableFrom(ByteArrayResource.class)) {
return Mono.from(byteArray.map(ByteArrayResource::new));
}
else {
return Mono.error(new IllegalStateException("Unsupported resource class: " + clazz));
}
}
}