code: public static String addImpliedHttpIfNecessary(String u) {
          int colon = u.indexOf(':');
          int period = u.indexOf('.');
          if (colon == -1 || (period >= 0) && (period < colon)) {
              // No scheme present; prepend "http://"
              u = "http://" + u;
          }
          return u;
      }
docs: Given a string that may be a plain host or host/path (without
  URI scheme), add an implied http:// if necessary.
  
  @param u string to evaluate
  @return string with http:// added if no scheme already present