/*
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
* 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.xwiki.store.serialization.xml.internal;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.xml.sax.SAXException;
import org.xwiki.component.annotation.ComponentRole;
import org.xwiki.store.serialization.xml.XMLSerializer;
/**
* A Serializer which converts objects into XML Elements and back.
*
* @param <R> The class of object which the serializer can serialize (what it requires).
* @param <P> The class of object which will be provided by this serializer when it parses data.
* @version $Id: 9190cbe2d0953b5785682045b78dec1980c9bd98 $
* @since 3.0M2
*/
// Note: We cannot replace @ComponentRole with @Role ATM since @Role supports generics and we have
// AbstractXMLSerializer<R, P extends R>. Changing it will thus break all code looking up components implementing this
// role.
@ComponentRole
public abstract class AbstractXMLSerializer<R, P extends R> implements XMLSerializer<R, P>
{
@Override
public InputStream serialize(final R object) throws IOException
{
// This puts everything on the heap for now.
// if size becomes a major problem, the alternitive is to fork over another thread
// and use a PipedInputStream.
final ByteArrayOutputStream baos = new ByteArrayOutputStream();
final XMLWriter writer;
try {
// This should always be UTF-8 because it is a property of the serializer.
final OutputFormat of = new OutputFormat(" ", true, "UTF-8");
writer = new XMLWriter(baos, of);
writer.startDocument();
} catch (SAXException e) {
throw new IOException("Could not open the XML writer.");
}
this.serialize(object, writer);
try {
writer.endDocument();
} catch (SAXException e) {
throw new IOException("Could not close the XML writer.");
}
return new ByteArrayInputStream(baos.toByteArray());
}
@Override
public P parse(final InputStream stream) throws IOException
{
final SAXReader reader = new SAXReader();
// Remove nodes generated by indentation.
reader.setStripWhitespaceText(true);
reader.setMergeAdjacentText(true);
final Document domdoc;
try {
domdoc = reader.read(stream);
} catch (DocumentException e) {
throw new IOException("Failed to parse XML, probably malformed input.");
}
return this.parse(domdoc.getRootElement());
}
}