code: public InputSource resolveEntity( String pPublicId, String pSystemId )
          throws SAXException, IOException
      {
          final InputSource source = resolver.resolveEntity( pPublicId, pSystemId );
          if ( source != null )
          {
              return source;
          }
  
          URL url = resolve( pSystemId );
          if ( url != null )
          {
              return asInputSource( url );
          }
          return null;
      }
docs: Implementation of {@link org.xml.sax.EntityResolver#resolveEntity(String, String)}.