/*
* Copyright (C) 2009 eXo Platform SAS.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.exoplatform.services.rest.ext.provider;
import org.exoplatform.common.util.HierarchicalProperty;
import org.exoplatform.services.log.ExoLogger;
import org.exoplatform.services.log.Log;
import org.exoplatform.services.rest.provider.EntityProvider;
import org.w3c.dom.Document;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.LinkedList;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.Provider;
import javax.xml.namespace.QName;
import javax.xml.stream.EventFilter;
import javax.xml.stream.FactoryConfigurationError;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.Characters;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
/**
* Converts stream to {@link HierarchicalProperty} and serializes
* {@link HierarchicalProperty} in given stream.
*
* @author <a href="dkatayev@gmail.com">Dmytro Katayev</a>
* @version $Id: HierarchicalPropertyEntityProvider.java
*/
@Provider
public class HierarchicalPropertyEntityProvider implements EntityProvider<HierarchicalProperty>
{
/**
* Logger.
*/
private static final Log LOG = ExoLogger.getLogger("exo.ws.rest.ext.HierarchicalPropertyEntityProvider");
/**
* {@inheritDoc}
*/
public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType)
{
return type == HierarchicalProperty.class;
}
/**
* {@inheritDoc}
*/
public HierarchicalProperty readFrom(Class<HierarchicalProperty> t, Type genericType, Annotation[] annotations,
MediaType mediaType, MultivaluedMap<String, String> httpHeaders, InputStream entityStream) throws IOException,
WebApplicationException
{
HierarchicalProperty rootProperty = null;
LinkedList<HierarchicalProperty> curProperty = new LinkedList<HierarchicalProperty>();
try
{
XMLInputFactory factory = XMLInputFactory.newInstance();
XMLEventReader reader = factory.createXMLEventReader(entityStream);
XMLEventReader fReader = factory.createFilteredReader(reader, new EventFilter()
{
public boolean accept(XMLEvent event)
{
return !(event.isCharacters() && ((Characters)event).isWhiteSpace());
}
});
while (fReader.hasNext())
{
XMLEvent event = fReader.nextEvent();
switch (event.getEventType())
{
case XMLEvent.START_ELEMENT :
StartElement element = event.asStartElement();
QName name = element.getName();
HierarchicalProperty prop = new HierarchicalProperty(name);
if (!curProperty.isEmpty())
curProperty.getLast().addChild(prop);
else
rootProperty = prop;
curProperty.addLast(prop);
break;
case XMLEvent.END_ELEMENT :
curProperty.removeLast();
break;
case XMLEvent.CHARACTERS :
String chars = event.asCharacters().getData();
curProperty.getLast().setValue(chars);
break;
default :
break;
}
}
return rootProperty;
}
catch (FactoryConfigurationError e)
{
throw new IOException(e.getMessage());
}
catch (XMLStreamException e)
{
if (LOG.isDebugEnabled())
LOG.debug("An XMLStreamException occurs", e);
return null;
}
catch (RuntimeException re)
{
String reName = re.getClass().getName();
if (reName.equals("com.ctc.wstx.exc.WstxLazyException"))
{
if (LOG.isDebugEnabled())
LOG.error(re.getMessage(), re);
return null;
}
else
{
throw re;
}
}
}
/**
* {@inheritDoc}
*/
public long getSize(HierarchicalProperty t, Class<?> type, Type genericType, Annotation[] annotations,
MediaType mediaType)
{
return -1;
}
/**
* {@inheritDoc}
*/
public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType)
{
return HierarchicalProperty.class.isAssignableFrom(type);
}
/**
* {@inheritDoc}
*/
public void writeTo(HierarchicalProperty t, Class<?> type, Type genericType, Annotation[] annotations,
MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException,
WebApplicationException
{
Document e = (Document)t;
try
{
TransformerFactory.newInstance().newTransformer().transform(new DOMSource(e), new StreamResult(entityStream));
}
catch (TransformerException tre)
{
throw new IOException("Can't write to output stream " + tre);
}
}
}