/*
* 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.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.amqp.utils.SerializationUtils;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.remoting.rmi.CodebaseAwareObjectInputStream;
import org.springframework.util.ClassUtils;
/**
* Implementation of {@link MessageConverter} that can work with Strings, Serializable instances,
* or byte arrays. The {@link #toMessage(Object, MessageProperties)} method simply checks the
* type of the provided instance while the {@link #fromMessage(Message)} method relies upon the
* {@link MessageProperties#getContentType() content-type} of the provided Message.
*
* @author Mark Fisher
* @author Oleg Zhurakousky
*/
public class SimpleMessageConverter extends AbstractMessageConverter implements BeanClassLoaderAware {
public static final String DEFAULT_CHARSET = "UTF-8";
private volatile String defaultCharset = DEFAULT_CHARSET;
private String codebaseUrl;
private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();
@Override
public void setBeanClassLoader(ClassLoader beanClassLoader) {
this.beanClassLoader = beanClassLoader;
}
/**
* Set the codebase URL to download classes from if not found locally. Can consists of multiple URLs, separated by
* spaces.
* <p>
* Follows RMI's codebase conventions for dynamic class download.
*
* @param codebaseUrl The codebase URL.
*
* @see org.springframework.remoting.rmi.CodebaseAwareObjectInputStream
* @see java.rmi.server.RMIClassLoader
*/
public void setCodebaseUrl(String codebaseUrl) {
this.codebaseUrl = codebaseUrl;
}
/**
* Specify the default charset to use when converting to or from text-based
* Message body content. If not specified, the charset will be "UTF-8".
*
* @param defaultCharset The default charset.
*/
public void setDefaultCharset(String defaultCharset) {
this.defaultCharset = (defaultCharset != null) ? defaultCharset : DEFAULT_CHARSET;
}
/**
* Converts from a AMQP Message to an Object.
*/
@Override
public Object fromMessage(Message message) throws MessageConversionException {
Object content = null;
MessageProperties properties = message.getMessageProperties();
if (properties != null) {
String contentType = properties.getContentType();
if (contentType != null && contentType.startsWith("text")) {
String encoding = properties.getContentEncoding();
if (encoding == null) {
encoding = this.defaultCharset;
}
try {
content = new String(message.getBody(), encoding);
}
catch (UnsupportedEncodingException e) {
throw new MessageConversionException(
"failed to convert text-based Message content", e);
}
}
else if (contentType != null &&
contentType.equals(MessageProperties.CONTENT_TYPE_SERIALIZED_OBJECT)) {
try {
content = SerializationUtils.deserialize(createObjectInputStream(new ByteArrayInputStream(message.getBody()), this.codebaseUrl));
} catch (IOException e) {
throw new MessageConversionException(
"failed to convert serialized Message content", e);
} catch (IllegalArgumentException e) {
throw new MessageConversionException(
"failed to convert serialized Message content", e);
}
}
}
if (content == null) {
content = message.getBody();
}
return content;
}
/**
* Creates an AMQP Message from the provided Object.
*/
@Override
protected Message createMessage(Object object, MessageProperties messageProperties) throws MessageConversionException {
byte[] bytes = null;
if (object instanceof byte[]) {
bytes = (byte[]) object;
messageProperties.setContentType(MessageProperties.CONTENT_TYPE_BYTES);
}
else if (object instanceof String) {
try {
bytes = ((String) object).getBytes(this.defaultCharset);
}
catch (UnsupportedEncodingException e) {
throw new MessageConversionException(
"failed to convert to Message content", e);
}
messageProperties.setContentType(MessageProperties.CONTENT_TYPE_TEXT_PLAIN);
messageProperties.setContentEncoding(this.defaultCharset);
}
else if (object instanceof Serializable) {
try {
bytes = SerializationUtils.serialize(object);
} catch (IllegalArgumentException e) {
throw new MessageConversionException(
"failed to convert to serialized Message content", e);
}
messageProperties.setContentType(MessageProperties.CONTENT_TYPE_SERIALIZED_OBJECT);
}
if (bytes != null) {
messageProperties.setContentLength(bytes.length);
}
return new Message(bytes, messageProperties);
}
/**
* Create an ObjectInputStream for the given InputStream and codebase. The default implementation creates a
* CodebaseAwareObjectInputStream.
* @param is the InputStream to read from
* @param codebaseUrl the codebase URL to load classes from if not found locally (can be <code>null</code>)
* @return the new ObjectInputStream instance to use
* @throws IOException if creation of the ObjectInputStream failed
* @see org.springframework.remoting.rmi.CodebaseAwareObjectInputStream
*/
protected ObjectInputStream createObjectInputStream(InputStream is, String codebaseUrl) throws IOException {
return new CodebaseAwareObjectInputStream(is, this.beanClassLoader, codebaseUrl);
}
}