org.springframework.core.codec.ResourceEncoder Maven / Gradle / Ivy
/*
* Copyright 2002-2019 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 reactor.core.publisher.Flux;
import org.springframework.core.ResolvableType;
import org.springframework.core.io.Resource;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.MimeType;
import org.springframework.util.MimeTypeUtils;
import org.springframework.util.StreamUtils;
/**
* Encoder for {@link Resource Resources}.
*
* @author Arjen Poutsma
* @since 5.0
*/
public class ResourceEncoder extends AbstractSingleValueEncoder {
/**
* The default buffer size used by the encoder.
*/
public static final int DEFAULT_BUFFER_SIZE = StreamUtils.BUFFER_SIZE;
private final int bufferSize;
public ResourceEncoder() {
this(DEFAULT_BUFFER_SIZE);
}
public ResourceEncoder(int bufferSize) {
super(MimeTypeUtils.APPLICATION_OCTET_STREAM, MimeTypeUtils.ALL);
Assert.isTrue(bufferSize > 0, "'bufferSize' must be larger than 0");
this.bufferSize = bufferSize;
}
@Override
public boolean canEncode(ResolvableType elementType, @Nullable MimeType mimeType) {
Class clazz = elementType.toClass();
return (super.canEncode(elementType, mimeType) && Resource.class.isAssignableFrom(clazz));
}
@Override
protected Flux encode(Resource resource, DataBufferFactory bufferFactory,
ResolvableType type, @Nullable MimeType mimeType, @Nullable Map hints) {
if (logger.isDebugEnabled() && !Hints.isLoggingSuppressed(hints)) {
String logPrefix = Hints.getLogPrefix(hints);
logger.debug(logPrefix + "Writing [" + resource + "]");
}
return DataBufferUtils.read(resource, bufferFactory, this.bufferSize);
}
}