/**
* Copyright 2005-2013 Restlet S.A.S.
*
* The contents of this file are subject to the terms of one of the following
* open source licenses: Apache 2.0 or LGPL 3.0 or LGPL 2.1 or CDDL 1.0 or EPL
* 1.0 (the "Licenses"). You can select the license that you prefer but you may
* not use this file except in compliance with one of these Licenses.
*
* You can obtain a copy of the Apache 2.0 license at
* http://www.opensource.org/licenses/apache-2.0
*
* You can obtain a copy of the LGPL 3.0 license at
* http://www.opensource.org/licenses/lgpl-3.0
*
* You can obtain a copy of the LGPL 2.1 license at
* http://www.opensource.org/licenses/lgpl-2.1
*
* You can obtain a copy of the CDDL 1.0 license at
* http://www.opensource.org/licenses/cddl1
*
* You can obtain a copy of the EPL 1.0 license at
* http://www.opensource.org/licenses/eclipse-1.0
*
* See the Licenses for the specific language governing permissions and
* limitations under the Licenses.
*
* Alternatively, you can obtain a royalty free commercial license with less
* limitations, transferable or non-transferable, directly at
* http://www.restlet.com/products/restlet-framework
*
* Restlet is a registered trademark of Restlet S.A.S.
*/
package org.restlet.ext.xml;
import java.io.IOException;
import java.io.Writer;
import javax.xml.XMLConstants;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.Result;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.TransformerFactoryConfigurationError;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.sax.SAXSource;
import org.restlet.data.MediaType;
import org.restlet.representation.Representation;
import org.w3c.dom.Document;
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;
/**
* XML representation for SAX events processing. The purpose is to create a
* streamable content based on a custom Java object model instead of a neutral
* DOM tree. This domain object can then be directly modified and efficiently
* serialized at a later time.
*
* Subclasses only need to override the ContentHandler methods required for the
* reading and also the write(XmlWriter writer) method when serialization is
* requested.
*
* @author Jerome Louvel
*/
public class SaxRepresentation extends XmlRepresentation {
/** Limits potential XML overflow attacks. */
private boolean secureProcessing;
/** The SAX source. */
private volatile SAXSource source;
/** The source XML representation. */
private volatile Representation xmlRepresentation;
/**
* Default constructor. Uses the {@link MediaType#TEXT_XML} media type.
*/
public SaxRepresentation() {
this(MediaType.TEXT_XML);
}
/**
* Constructor.
*
* @param mediaType
* The representation media type.
*/
public SaxRepresentation(MediaType mediaType) {
super(mediaType);
this.secureProcessing = false;
}
/**
* Constructor.
*
* @param mediaType
* The representation's media type.
* @param xmlDocument
* A DOM document to parse.
*/
public SaxRepresentation(MediaType mediaType, Document xmlDocument) {
super(mediaType);
this.secureProcessing = false;
this.source = new SAXSource(
SAXSource.sourceToInputSource(new DOMSource(xmlDocument)));
}
/**
* Constructor.
*
* @param mediaType
* The representation's media type.
* @param xmlSource
* A SAX input source to parse.
*/
public SaxRepresentation(MediaType mediaType, InputSource xmlSource) {
super(mediaType);
this.secureProcessing = false;
this.source = new SAXSource(xmlSource);
}
/**
* Constructor.
*
* @param mediaType
* The representation's media type.
* @param xmlSource
* A JAXP source to parse.
*/
public SaxRepresentation(MediaType mediaType, SAXSource xmlSource) {
super(mediaType);
this.secureProcessing = false;
this.source = xmlSource;
}
/**
* Constructor.
*
* @param xmlRepresentation
* A source XML representation to parse.
*/
public SaxRepresentation(Representation xmlRepresentation) {
super((xmlRepresentation == null) ? null : xmlRepresentation
.getMediaType());
this.secureProcessing = false;
this.xmlRepresentation = xmlRepresentation;
}
@Override
public InputSource getInputSource() throws IOException {
return (getSaxSource() == null) ? null : getSaxSource()
.getInputSource();
}
/**
* Returns the SAX source that can be parsed by the
* {@link #parse(ContentHandler)} method or used for an XSLT transformation.
*/
@Override
public SAXSource getSaxSource() throws IOException {
if (this.source == null && this.xmlRepresentation != null) {
if (xmlRepresentation instanceof XmlRepresentation) {
this.source = ((XmlRepresentation) xmlRepresentation)
.getSaxSource();
} else {
try {
SAXParserFactory spf = SAXParserFactory.newInstance();
// Keep before the external entity preferences
spf.setValidating(isValidatingDtd());
javax.xml.validation.Schema xsd = getSchema();
if (xsd != null) {
spf.setSchema(xsd);
}
spf.setNamespaceAware(isNamespaceAware());
spf.setXIncludeAware(isXIncludeAware());
spf.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING,
isSecureProcessing());
spf.setFeature(
"http://xml.org/sax/features/external-general-entities",
isExpandingEntityRefs());
spf.setFeature(
"http://xml.org/sax/features/external-parameter-entities",
isExpandingEntityRefs());
XMLReader xmlReader = spf.newSAXParser().getXMLReader();
this.source = new SAXSource(xmlReader, new InputSource(
xmlRepresentation.getReader()));
} catch (Exception e) {
throw new IOException(
"Unable to create customized SAX source");
}
}
if (xmlRepresentation.getLocationRef() != null) {
this.source.setSystemId(xmlRepresentation.getLocationRef()
.getTargetRef().toString());
}
}
return this.source;
}
/**
* Indicates if it limits potential XML overflow attacks.
*
* @return True if it limits potential XML overflow attacks.
*/
public boolean isSecureProcessing() {
return secureProcessing;
}
/**
* Parses the source and sends SAX events to a content handler.
*
* @param contentHandler
* The SAX content handler to use for parsing.
*/
public void parse(ContentHandler contentHandler) throws IOException {
if (contentHandler != null) {
try {
Result result = new SAXResult(contentHandler);
TransformerFactory.newInstance().newTransformer()
.transform(getSaxSource(), result);
} catch (TransformerConfigurationException tce) {
throw new IOException(
"Couldn't parse the source representation: "
+ tce.getMessage());
} catch (TransformerException te) {
te.printStackTrace();
throw new IOException(
"Couldn't parse the source representation: "
+ te.getMessage());
} catch (TransformerFactoryConfigurationError tfce) {
throw new IOException(
"Couldn't parse the source representation: "
+ tfce.getMessage());
}
} else {
throw new IOException(
"Couldn't parse the source representation: no content restlet defined.");
}
}
/**
* Releases the namespaces map.
*/
@Override
public void release() {
if (this.source != null) {
this.source = null;
}
if (this.xmlRepresentation != null) {
this.xmlRepresentation.release();
}
super.release();
}
/**
* Sets a SAX source that can be parsed by the
* {@link #parse(ContentHandler)} method.
*
* @param source
* A SAX source.
*/
public void setSaxSource(SAXSource source) {
this.source = source;
}
/**
* Indicates if it limits potential XML overflow attacks.
*
* @param secureProcessing
* True if it limits potential XML overflow attacks.
*/
public void setSecureProcessing(boolean secureProcessing) {
this.secureProcessing = secureProcessing;
}
@Override
public void write(Writer writer) throws IOException {
XmlWriter xmlWriter = new XmlWriter(writer);
write(xmlWriter);
}
/**
* Writes the representation to a XML writer. The default implementation
* calls {@link #parse(ContentHandler)} using the {@link XmlWriter}
* parameter as the content handler. This behavior is intended to be
* overridden.
*
* @param writer
* The XML writer to write to.
* @throws IOException
*/
public void write(XmlWriter writer) throws IOException {
parse(writer);
}
}