code: public static boolean validateIntegerParam(final Map<String, String> params,
        final String paramName) throws ExecutorManagerException {
      if (params != null && params.containsKey(paramName)
          && !StringUtils.isNumeric(params.get(paramName))) {
        throw new ExecutorManagerException(paramName + " should be an integer");
      }
      return true;
    }
docs: parse a string as number and throws exception if parsed value is not a valid integer
  
  @throws ExecutorManagerException if paramName is not a valid integer