code: public InputSource resolveEntity(String publicId, String systemId)
            throws SAXException, IOException
    {
  
      if (m_entityResolver != null)
      {
        return m_entityResolver.resolveEntity(publicId, systemId);
      }
      else
      {
        return null;
      }
    }
docs: Filter an external entity resolution.
  
  @param publicId The entity's public identifier, or null.
  @param systemId The entity's system identifier.
  @return A new InputSource or null for the default.
  
  @throws IOException
  @throws SAXException The client may throw
  an exception during processing.
  @throws java.io.IOException The client may throw an
  I/O-related exception while obtaining the
  new InputSource.
  @see org.xml.sax.EntityResolver#resolveEntity