/*
* Copyright 2002-2014 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.converter;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.oxm.Marshaller;
import org.springframework.oxm.Unmarshaller;
import org.springframework.oxm.XmlMappingException;
import org.springframework.util.Assert;
/**
* Spring Rabbit {@link MessageConverter} that uses a {@link Marshaller} and {@link Unmarshaller}.
* Marshals an object to a {@link Message} and unmarshals a {@link Message} to an object.
*
* @author Mark Fisher
* @author Arjen Poutsma
* @author Juergen Hoeller
* @author James Carr
* @see org.springframework.amqp.core.AmqpTemplate#convertAndSend(Object)
* @see org.springframework.amqp.core.AmqpTemplate#receiveAndConvert()
*/
public class MarshallingMessageConverter extends AbstractMessageConverter implements InitializingBean {
private volatile Marshaller marshaller;
private volatile Unmarshaller unmarshaller;
private volatile String contentType;
/**
* Construct a new <code>MarshallingMessageConverter</code> with no {@link Marshaller} or {@link Unmarshaller} set.
* The marshaller must be set after construction by invoking {@link #setMarshaller(Marshaller)} and
* {@link #setUnmarshaller(Unmarshaller)} .
*/
public MarshallingMessageConverter() {
}
/**
* Construct a new <code>MarshallingMessageConverter</code> with the given {@link Marshaller} set.
* <p>If the given {@link Marshaller} also implements the {@link Unmarshaller} interface,
* it is used for both marshalling and unmarshalling. Otherwise, an exception is thrown.
* <p>Note that all {@link Marshaller} implementations in Spring also implement the
* {@link Unmarshaller} interface, so that you can safely use this constructor.
* @param marshaller object used as marshaller and unmarshaller
* @throws IllegalArgumentException when <code>marshaller</code> does not implement the
* {@link Unmarshaller} interface as well
*/
public MarshallingMessageConverter(Marshaller marshaller) {
Assert.notNull(marshaller, "marshaller must not be null");
if (!(marshaller instanceof Unmarshaller)) {
throw new IllegalArgumentException(
"Marshaller [" + marshaller + "] does not implement the Unmarshaller " +
"interface. Please set an Unmarshaller explicitly by using the " +
"MarshallingMessageConverter(Marshaller, Unmarshaller) constructor.");
}
else {
this.marshaller = marshaller;
this.unmarshaller = (Unmarshaller) marshaller;
}
}
/**
* Construct a new <code>MarshallingMessageConverter</code> with the
* given Marshaller and Unmarshaller.
* @param marshaller the Marshaller to use
* @param unmarshaller the Unmarshaller to use
*/
public MarshallingMessageConverter(Marshaller marshaller, Unmarshaller unmarshaller) {
Assert.notNull(marshaller, "marshaller must not be null");
Assert.notNull(unmarshaller, "unmarshaller must not be null");
this.marshaller = marshaller;
this.unmarshaller = unmarshaller;
}
/**
* Set the contentType to be used by this message converter.
*
* @param contentType The content type.
*/
public void setContentType(String contentType) {
this.contentType = contentType;
}
/**
* Set the {@link Marshaller} to be used by this message converter.
*
* @param marshaller The marshaller.
*/
public void setMarshaller(Marshaller marshaller) {
Assert.notNull(marshaller, "marshaller must not be null");
this.marshaller = marshaller;
}
/**
* Set the {@link Unmarshaller} to be used by this message converter.
*
* @param unmarshaller The unmarshaller.
*/
public void setUnmarshaller(Unmarshaller unmarshaller) {
Assert.notNull(unmarshaller, "unmarshaller must not be null");
this.unmarshaller = unmarshaller;
}
@Override
public void afterPropertiesSet() {
Assert.notNull(this.marshaller, "Property 'marshaller' is required");
Assert.notNull(this.unmarshaller, "Property 'unmarshaller' is required");
}
/**
* Marshals the given object to a {@link Message}.
*/
@Override
protected Message createMessage(Object object, MessageProperties messageProperties) throws MessageConversionException {
try {
if (this.contentType != null) {
messageProperties.setContentType(this.contentType);
}
ByteArrayOutputStream bos = new ByteArrayOutputStream();
StreamResult streamResult = new StreamResult(bos);
this.marshaller.marshal(object, streamResult);
return new Message(bos.toByteArray(), messageProperties);
}
catch (XmlMappingException ex) {
throw new MessageConversionException("Could not marshal [" + object + "]", ex);
}
catch (IOException ex) {
throw new MessageConversionException("Could not marshal [" + object + "]", ex);
}
}
/**
* Unmarshals the given {@link Message} into an object.
*/
@Override
public Object fromMessage(Message message) throws MessageConversionException {
try {
ByteArrayInputStream bis = new ByteArrayInputStream(message.getBody());
StreamSource source = new StreamSource(bis);
return this.unmarshaller.unmarshal(source);
}
catch (IOException ex) {
throw new MessageConversionException("Could not access message content: " + message, ex);
}
catch (XmlMappingException ex) {
throw new MessageConversionException("Could not unmarshal message: " + message, ex);
}
}
}