//Setup FOP
Fop fop = fopFactory.newFop(MimeConstants.MIME_PDF, out);
//Setup Transformer
Source xsltSrc = new StreamSource(new File(xslPath));
Transformer transformer = tFactory.newTransformer(xsltSrc);

//Make sure the XSL transformation's result is piped through to FOP
Result res = new SAXResult(fop.getDefaultHandler());
//Setup input
Source src = new StreamSource(new File(xmlPath));
//Start the transformation and rendering process
transformer.transform(src, res);

ClassLoader cl = this.getClass().getClassLoader();
String systemID = "resources/xslt/myfile.xslt";
InputStream in = cl.getResourceAsStream(systemID);
URL url = cl.getResource(systemID);
Source source = new StreamSource(in);
source.setSystemId(url.toExternalForm());
transformer = tFactory.newTransformer(source);

// construct a Source that reads from an InputStream
Source mySrc = new StreamSource(anInputStream);
// specify a system ID (a String) so the
// Source can resolve relative URLs
// that are encountered in XSLT stylesheets
mySrc.setSystemId(aSystemId);

TransformerFactory transFact = TransformerFactory.newInstance();
StreamSource xsltSource = new StreamSource(xsl);

// XXX for 'xsl:import' to load other xsls from class path
transFact.setURIResolver(new ClasspathResourceURIResolver());
Templates cachedXSLT = transFact.newTemplates(xsltSource);
Transformer transformer = cachedXSLT.newTransformer();


class ClasspathResourceURIResolver implements URIResolver {
  @Override
  public Source resolve(String href, String base) throws TransformerException {
    return new StreamSource(XXX.getClassLoader().getResourceAsStream(href));
  }
}

<xsl:import href="META-INF/companybusinesscredit/imported.xsl"/>

JarfileResolver jarfileResolver = new JarfileResolver();
transformer.setURIResolver(jarfileResolver);


public class JarfileResolver implements URIResolver
{
    public Source resolve(String fileName, String base) throws TransformerException
    {
        URL url = getClass().getClassLoader().getResource(fileName);
        StreamSource jarFileSS = new StreamSource();

        try
        {
            InputStream jarfileIS = url.openStream();
            jarFileSS.setInputStream(jarfileIS);
        }
        catch(IOException ioExp)
        {
            throw new TransformerException(ioExp);
        }
        return jarFileSS;
    }
}