docs: protected URL resolveHandlerChainFileName(String clzName, String fileName) {
          URL handlerFile = null;
          InputStream in = null;
  
          String handlerChainFileName = fileName;
          URL baseUrl = classLoader.getResource(getClassResourceName(clzName));
  
          try {
              //if the filename start with '/', then find and return the resource under the web application home directory directory.
              if (handlerChainFileName.charAt(0) == '/') {
                  return classLoader.getResource(handlerChainFileName.substring(1));
              }
  
              //otherwise, create a new url instance according to the baseurl and the fileName
              handlerFile = new URL(baseUrl, handlerChainFileName);
              in = handlerFile.openStream();
          } catch (Exception e) {
              // log the error msg
          } finally {
              if (in != null) {
                  try {
                      in.close();
                  } catch (Exception e) {
                  }
              }
          }
          return handlerFile;
      }