org.springframework.core.codec.DataBufferDecoder Maven / Gradle / Ivy
/*
* Copyright 2002-2022 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.util.Map;
import org.reactivestreams.Publisher;
import reactor.core.publisher.Flux;
import org.springframework.core.ResolvableType;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.lang.Nullable;
import org.springframework.util.MimeType;
import org.springframework.util.MimeTypeUtils;
/**
* Simple pass-through decoder for {@link DataBuffer DataBuffers}.
*
* Note: The data buffers should be released via
* {@link org.springframework.core.io.buffer.DataBufferUtils#release(DataBuffer)}
* after they have been consumed. In addition, if using {@code Flux} or
* {@code Mono} operators such as flatMap, reduce, and others that prefetch,
* cache, and skip or filter out data items internally, please add
* {@code doOnDiscard(DataBuffer.class, DataBufferUtils::release)} to the
* composition chain to ensure cached data buffers are released prior to an
* error or cancellation signal.
*
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @since 5.0
*/
public class DataBufferDecoder extends AbstractDataBufferDecoder {
public DataBufferDecoder() {
super(MimeTypeUtils.ALL);
}
@Override
public boolean canDecode(ResolvableType elementType, @Nullable MimeType mimeType) {
return (DataBuffer.class.isAssignableFrom(elementType.toClass()) &&
super.canDecode(elementType, mimeType));
}
@Override
public Flux decode(Publisher input, ResolvableType elementType,
@Nullable MimeType mimeType, @Nullable Map hints) {
return Flux.from(input);
}
@Override
public DataBuffer decode(DataBuffer buffer, ResolvableType elementType,
@Nullable MimeType mimeType, @Nullable Map hints) {
if (logger.isDebugEnabled()) {
logger.debug(Hints.getLogPrefix(hints) + "Read " + buffer.readableByteCount() + " bytes");
}
return buffer;
}
}