Get Tomcat Port Number from Java Code line

This code reads the port number defined in Server.XML of Tomcat, the code source is http://www.asjava.com/tomcat/how-to-get-tomcat-port-number-in-java/

public static Integer getTomcatPortFromConfigXml(File serverXml) {
 
  Integer port;
  try {
    DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
    domFactory.setNamespaceAware(true); // never forget this!
    DocumentBuilder builder = domFactory.newDocumentBuilder();
    Document doc = builder.parse(serverXml);
    XPathFactory factory = XPathFactory.newInstance();
    XPath xpath = factory.newXPath();
    XPathExpression expr = xpath.compile("/Server/Service[@name='Catalina']/Connector[count(@scheme)=0]/@port[1]");
    String result = (String) expr.evaluate(doc, XPathConstants.STRING);
    port =  result != null && result.length() > 0 ? Integer.valueOf(result) : null;
  } catch (Exception e) {
    port = null;
  }
  return port;
}