/*
* $Id: ObjectToJson.java 20321 2010-11-24 15:21:24Z dfeist $
* --------------------------------------------------------------------------------------
* Copyright (c) MuleSoft, Inc. All rights reserved. http://www.mulesoft.com
*
* The software in this package is published under the terms of the CPAL v1.0
* license, a copy of which has been included with this distribution in the
* LICENSE.txt file.
*/
package org.mule.module.json.transformers;
import org.mule.api.MuleMessage;
import org.mule.api.lifecycle.InitialisationException;
import org.mule.api.transformer.TransformerException;
import org.mule.module.json.filters.IsJsonFilter;
import org.mule.transformer.types.DataTypeFactory;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.io.IOException;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Converts a java object to a JSON encoded object that can be consumed by other languages such as
* Javascript or Ruby.
* <p/>
* The returnClass for this transformer is always java.lang.String, there is no need to set this.
*/
public class ObjectToJson extends AbstractJsonTransformer
{
/**
* logger used by this class
*/
protected transient final Log logger = LogFactory.getLog(ObjectToJson.class);
private Map<Class<?>, Class<?>> serializationMixins = new HashMap<Class<?>, Class<?>>();
protected Class<?> sourceClass;
private boolean handleException = false;
private IsJsonFilter isJsonFilter = new IsJsonFilter();
public ObjectToJson()
{
this.setReturnDataType(DataTypeFactory.JSON_STRING);
}
@Override
public void initialise() throws InitialisationException
{
super.initialise();
//restrict the handled types
if (getSourceClass() != null)
{
sourceTypes.clear();
registerSourceType(DataTypeFactory.create(getSourceClass()));
}
//Add shared mixins first
for (Map.Entry<Class<?>, Class<?>> entry : getMixins().entrySet())
{
getMapper().getSerializationConfig().addMixInAnnotations(entry.getKey(), entry.getValue());
}
for (Map.Entry<Class<?>, Class<?>> entry : serializationMixins.entrySet())
{
getMapper().getSerializationConfig().addMixInAnnotations(entry.getKey(), entry.getValue());
}
}
@Override
public Object transformMessage(MuleMessage message, String outputEncoding) throws TransformerException
{
Object src = message.getPayload();
if (src instanceof String && isJsonFilter.accept(src))
{
//Nothing to transform
return src;
}
// Checks if there's an exception
if (message.getExceptionPayload() != null && this.isHandleException())
{
if (logger.isDebugEnabled())
{
logger.debug("Found exception with null payload");
}
src = this.getException(message.getExceptionPayload().getException());
}
StringWriter writer = new StringWriter();
try
{
getMapper().writeValue(writer, src);
}
catch (IOException e)
{
throw new TransformerException(this, e);
}
if (returnType.getType().equals(byte[].class))
{
try
{
return writer.toString().getBytes(outputEncoding);
}
catch (UnsupportedEncodingException uee)
{
throw new TransformerException(this, uee);
}
}
else
{
return writer.toString();
}
}
/**
* The reason of having this is because the original exception object is way too
* complex and it breaks JSON-lib.
*/
private Exception getException(Throwable t)
{
Exception returnValue = null;
List<Throwable> causeStack = new ArrayList<Throwable>();
for (Throwable tempCause = t; tempCause != null; tempCause = tempCause.getCause())
{
causeStack.add(tempCause);
}
for (int i = causeStack.size() - 1; i >= 0; i--)
{
Throwable tempCause = causeStack.get(i);
// There is no cause at the very root
if (i == causeStack.size())
{
returnValue = new Exception(tempCause.getMessage());
returnValue.setStackTrace(tempCause.getStackTrace());
}
else
{
returnValue = new Exception(tempCause.getMessage(), returnValue);
returnValue.setStackTrace(tempCause.getStackTrace());
}
}
return returnValue;
}
public boolean isHandleException()
{
return this.handleException;
}
public void setHandleException(boolean handleException)
{
this.handleException = handleException;
}
public Class<?> getSourceClass()
{
return sourceClass;
}
public void setSourceClass(Class<?> sourceClass)
{
this.sourceClass = sourceClass;
}
public Map<Class<?>, Class<?>> getSerializationMixins()
{
return serializationMixins;
}
public void setSerializationMixins(Map<Class<?>, Class<?>> serializationMixins)
{
this.serializationMixins = serializationMixins;
}
}