TracingURIResolver.java

package org.tigris.juxy.builder;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.tigris.juxy.util.SAXUtil;
import org.tigris.juxy.util.XSLTEngineSupport;
import org.xml.sax.XMLFilter;
import org.xml.sax.XMLReader;

import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.URIResolver;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.sax.SAXSource;

/**
 * This URI resolver will return SAXSource with tracing filter applied.
 *
 * @author Pavel Sher
 */
public class TracingURIResolver implements URIResolver {
  private static final Log logger = LogFactory.getLog(TracingURIResolver.class);
  private URIResolver originalResolver;
  private XSLTEngineSupport engineSupport;

  public TracingURIResolver(URIResolver originalResolver, XSLTEngineSupport engineSupport) {
    assert originalResolver != null;
    this.originalResolver = originalResolver;
    this.engineSupport = engineSupport;
  }

  public Source resolve(String href, String base) throws TransformerException {
    Source source = originalResolver.resolve(href, base);
    if (source == null) return null;

    if (source instanceof DOMSource) {
      logger.warn("Tracing is not available for stylesheets passed as DOMSource object");
      return source;
    }

    XMLReader parentReader = null;
    if (source instanceof SAXSource)
      parentReader = ((SAXSource) source).getXMLReader();
    if (parentReader == null)
      parentReader = SAXUtil.newXMLReader();

    XMLFilter tracingFilter = new TracingFilter(engineSupport);
    tracingFilter.setParent(parentReader);

/*
        SimpleSerializer s = new SimpleSerializer();
        s.setOutputStream(System.out);
        s.setParent(tracingFilter);
*/

    SAXSource result = new SAXSource(SAXSource.sourceToInputSource(source));
    result.setXMLReader(tracingFilter);

    return result;
  }
}