Retrieve list of defined roles in java ee 5

I was wondering if it would be possible to retrieve the complete list of security roles defined in a web.xml file in the java code? And if so how to do it?

I am aware of the 'isUserInRole' method but I also want to handle cases where a role is requested but not defined (or spelled differently) in the web.xml file.

From stackoverflow Jasper

• As far as I know, there's no way do do this within the Servlet API. However, you can parse web.xml directly and extract the values yourself. I used dom4j below, but you can use whatever XML processing stuff you like:

  protected List<String> getSecurityRoles() {
   List<String> roles = new ArrayList<String>();
   ServletContext sc = this.getServletContext();
   InputStream is = sc.getResourceAsStream("/WEB-INF/web.xml");
  
   try {
    SAXReader reader = new SAXReader();
    Document doc = reader.read(is);
  
    Element webApp = doc.getRootElement();
  
    // Type safety warning:  dom4j doesn't use generics
    List<Element> roleElements = webApp.elements("security-role");
    for (Element roleEl : roleElements) {
     roles.add(roleEl.element("role-name").getText());
    }
   } catch (DocumentException e) {
    e.printStackTrace();
   }
  
   return roles;
  }
  

  Jasper : too bad the container offers no way to get that info, but this seems like a fine workaround. Thanks!
  From Ian McLaird