code: public static String getValue(String xpath, Document document) throws XPathExpressionException {
          XPath xPathProcessor = XPathFactory.newInstance().newXPath();
          return xPathProcessor.compile(xpath).evaluate(document);
      }
docs: The a "value" from an XML file using XPath.
  @param xpath The XPath expression to select the value.
  @param document The document from which the value is to be extracted.
  @return The data value. An empty {@link String} is returned when the expression does not evaluate
  to anything in the document.
  @throws XPathExpressionException Invalid XPath expression.
  @since 2.0