/* Copyright (c) 2002-2011 by XMLVM.org
*
* Project Info: http://www.xmlvm.org
*
* This program 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 library 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 library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
package org.xmlvm.proc;
import java.io.InputStream;
import java.io.StringWriter;
import java.util.HashMap;
import java.util.Map;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.URIResolver;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import net.sf.saxon.Controller;
import net.sf.saxon.jdom.DocumentWrapper;
import org.jdom.Document;
import org.xmlvm.Log;
import org.xmlvm.proc.out.OutputFile;
/**
* Utility class for running XSL transformations.
*/
public class XsltRunner
{
private static final String TAG= XsltRunner.class.getSimpleName();
private static Map<String, Transformer> transformers= new HashMap<String, Transformer>();
private XsltRunner()
{
// Utility class.
}
/**
* Runs an XSLT file on the given JDOM document.
*
* @param xsltFileName
* The name of the file that contains the XSLT definition.
* @param doc
* The JDOM document the XSL transformation should be applied to.
* @return The output file with the result of the transformation.
*/
public static OutputFile runXSLT(String xsltFileName, Document doc)
{
return runXSLT(xsltFileName, doc, null);
}
/**
* Runs an XSLT file on the given JDOM document.
*
* @param xsltFileName
* The name of the file that contains the XSLT definition.
* @param doc
* The JDOM document the XSL transformation should be applied to.
* The first index refers to the i-th parameter, the index will
* be 0 for the parameter name and 1 for the parameter value. See
* {@link Transformer#setParameter(String, Object)}
* @param xsltParams
* Parameters that should be applied to the transformation.
* @return The output file with the result of the transformation.
*/
public static OutputFile runXSLT(String xsltFileName, Document doc, String[][] xsltParams)
{
StringWriter writer= new StringWriter();
try
{
Transformer transformer= getTransformer(xsltFileName);
transformer.reset();
if (xsltParams != null)
{
for (int i= 0; i < xsltParams.length; i++)
transformer.setParameter(xsltParams[i][0], xsltParams[i][1]);
}
DocumentWrapper docw= new DocumentWrapper(doc, "", ((Controller) transformer).getConfiguration());
Result result= new StreamResult(writer);
transformer.transform(docw, result);
return new OutputFile(writer.toString());
}
catch (TransformerException e)
{
Log.error(TAG, e.getMessage());
}
return null;
}
/**
* Returns a transformer for the given XSLT file. If one already exists, it
* will be returned and no new one will be created.
*
* @param xsltFileName
* the name of the XSLT file to use
* @return The transformer that uses the given XSLT file or null, if none
* could be created.
*/
private static Transformer getTransformer(String xsltFileName)
{
String key= xsltFileName + "-" + Thread.currentThread().getId();
if (transformers.containsKey(key))
{
return transformers.get(key);
}
InputStream xsltFile= XsltRunner.class.getResourceAsStream("/" + xsltFileName);
if (xsltFile == null)
{
Log.error(TAG, "Error could not find: " + xsltFileName);
return null;
}
try
{
Source xsltSource= new StreamSource(xsltFile);
TransformerFactory transFactory= TransformerFactory.newInstance();
// Add a URI resolver so that the XSL docs may import other XSL docs
// using relative paths
transFactory.setURIResolver(new URIResolver()
{
public Source resolve(String href, String base) throws TransformerException
{
InputStream is= XsltRunner.class.getResourceAsStream("/" + href);
return new StreamSource(is);
}
});
Transformer transformer= transFactory.newTransformer(xsltSource);
transformers.put(key, transformer);
return transformer;
}
catch (TransformerConfigurationException e)
{
Log.error(TAG, "Could not create transformer for " + xsltFileName + ": " + e.getMessage());
}
return null;
}
}