org.springframework.amqp.support.postprocessor.AbstractCompressingPostProcessor Maven / Gradle / Ivy
/*
* Copyright 2014-2017 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.amqp.support.postprocessor;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.amqp.AmqpException;
import org.springframework.amqp.AmqpIOException;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessagePostProcessor;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.core.Ordered;
import org.springframework.util.FileCopyUtils;
/**
* Base class for post processors that compress the message body. The content encoding is
* set to {@link #getEncoding()} or {@link #getEncoding()} + ":" + existing encoding, if
* present.
*
* @author Gary Russell
* @since 1.4.2
*/
public abstract class AbstractCompressingPostProcessor implements MessagePostProcessor, Ordered {
private final Log logger = LogFactory.getLog(this.getClass());
private final boolean autoDecompress;
private int order;
/**
* Construct a post processor that will include the
* {@link MessageProperties#SPRING_AUTO_DECOMPRESS} header set to 'true'.
*/
public AbstractCompressingPostProcessor() {
this(true);
}
/**
* Construct a post processor that will include (or not include) the
* {@link MessageProperties#SPRING_AUTO_DECOMPRESS} header. Used by the (Spring AMQP) inbound
* message converter to determine whether the message should be decompressed
* automatically, or remain compressed.
* @param autoDecompress true to indicate the receiver should automatically
* decompress.
*/
public AbstractCompressingPostProcessor(boolean autoDecompress) {
this.autoDecompress = autoDecompress;
}
@Override
public Message postProcessMessage(Message message) throws AmqpException {
ByteArrayOutputStream zipped = new ByteArrayOutputStream();
try {
OutputStream zipper = getCompressorStream(zipped);
FileCopyUtils.copy(new ByteArrayInputStream(message.getBody()), zipper);
MessageProperties messageProperties = message.getMessageProperties();
String currentEncoding = messageProperties.getContentEncoding();
messageProperties
.setContentEncoding(getEncoding() + (currentEncoding == null ? "" : ":" + currentEncoding));
if (this.autoDecompress) {
messageProperties.setHeader(MessageProperties.SPRING_AUTO_DECOMPRESS, true);
}
byte[] compressed = zipped.toByteArray();
if (this.logger.isTraceEnabled()) {
this.logger.trace("Compressed " + message.getBody().length + " to " + compressed.length);
}
return new Message(compressed, messageProperties);
}
catch (IOException e) {
throw new AmqpIOException(e);
}
}
@Override
public int getOrder() {
return this.order;
}
/**
* Set the order.
* @param order the order, default 0.
* @see Ordered
*/
protected void setOrder(int order) {
this.order = order;
}
/**
* Get the stream.
* @param stream The output stream to write the compressed data to.
* @return the compressor output stream.
* @throws IOException IOException
*/
protected abstract OutputStream getCompressorStream(OutputStream stream) throws IOException;
/**
* Get the encoding.
* @return the content-encoding header.
*/
protected abstract String getEncoding();
}