code: public static String encodeString(String str) {
          if (str == null)
              return str;
          if (str.equals("-1"))
              return str;
          try {
              Long lo = new Long(str);
              return encodeLong(lo.longValue());
          } catch (NumberFormatException nfe) {
              // do nothing -- this is expected on zOS, results in string being returned unchanged  242544
          } catch (Throwable th) {
              com.ibm.ws.ffdc.FFDCFilter.processException(th, "com.ibm.ws.session.utils.EncodeCloneID.encodeString", "56", str);
          }
          return str;
      }
docs: If unsuccessful returns the original as string