code: private void checkResourceURI(String resourceURI, String relName)
              throws SAXException {
  
          URI uri;
          try {
              uri = new URI(resourceURI);
          } catch (Exception e) {
              throw new SAXException("RelsExtValidator:"
                      + "Error in relationship '" + relName + "'."
                      + " The RDF 'resource' is not a valid URI.");
          }
  
          if (!uri.isAbsolute()) {
              throw new SAXException("RelsValidator:" + "Error in relationship '"
                      + relName + "'."
                      + " The specified RDF 'resource' is not an absolute URI.");
          }
      }
docs: checkResourceURI: ensure that the target resource is a proper URI.
  
  @param resourceURI
  the URI value of the RDF 'resource' attribute
  @param relName
  the name of the relationship property being evaluated
  @throws SAXException