org.springframework.core.codec.AbstractSingleValueEncoder 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
*
* 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.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.core.io.buffer.DataBufferFactory;
import org.springframework.lang.Nullable;
import org.springframework.util.MimeType;
/**
* Abstract base class for {@link org.springframework.core.codec.Encoder}
* classes that can only deal with a single value.
*
* @author Arjen Poutsma
* @since 5.0
* @param the element type
*/
public abstract class AbstractSingleValueEncoder extends AbstractEncoder {
public AbstractSingleValueEncoder(MimeType... supportedMimeTypes) {
super(supportedMimeTypes);
}
@Override
public final Flux encode(Publisher inputStream, DataBufferFactory bufferFactory,
ResolvableType elementType, @Nullable MimeType mimeType, @Nullable Map hints) {
return Flux.from(inputStream).
take(1).
concatMap(t -> encode(t, bufferFactory, elementType, mimeType, hints));
}
/**
* Encode {@code T} to an output {@link DataBuffer} stream.
* @param t the value to process
* @param dataBufferFactory a buffer factory used to create the output
* @param type the stream element type to process
* @param mimeType the mime type to process
* @param hints additional information about how to do decode, optional
* @return the output stream
*/
protected abstract Flux encode(T t, DataBufferFactory dataBufferFactory,
ResolvableType type, @Nullable MimeType mimeType, @Nullable Map hints);
}