org.springframework.core.codec.ResourceDecoder Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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.core.codec;
import java.io.ByteArrayInputStream;
import java.util.Map;
import org.reactivestreams.Publisher;
import reactor.core.publisher.Flux;
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.lang.Nullable;
import org.springframework.util.MimeType;
import org.springframework.util.MimeTypeUtils;
/**
* Decoder for {@link Resource Resources}.
*
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @since 5.0
*/
public class ResourceDecoder extends AbstractDataBufferDecoder {
public ResourceDecoder() {
super(MimeTypeUtils.ALL);
}
@Override
public boolean canDecode(ResolvableType elementType, @Nullable MimeType mimeType) {
return (Resource.class.isAssignableFrom(elementType.toClass()) &&
super.canDecode(elementType, mimeType));
}
@Override
public Flux decode(Publisher inputStream, ResolvableType elementType,
@Nullable MimeType mimeType, @Nullable Map hints) {
return Flux.from(decodeToMono(inputStream, elementType, mimeType, hints));
}
@Override
protected Resource decodeDataBuffer(DataBuffer dataBuffer, ResolvableType elementType,
@Nullable MimeType mimeType, @Nullable Map hints) {
byte[] bytes = new byte[dataBuffer.readableByteCount()];
dataBuffer.read(bytes);
DataBufferUtils.release(dataBuffer);
if (logger.isDebugEnabled()) {
logger.debug(Hints.getLogPrefix(hints) + "Read " + bytes.length + " bytes");
}
Class clazz = elementType.toClass();
if (clazz == InputStreamResource.class) {
return new InputStreamResource(new ByteArrayInputStream(bytes));
}
else if (Resource.class.isAssignableFrom(clazz)) {
return new ByteArrayResource(bytes);
}
else {
throw new IllegalStateException("Unsupported resource class: " + clazz);
}
}
}