There're 4 places in JDK with almost identical codes. They'd better be put into one single method.

        KrbTgsReq tgs_req = new KrbTgsReq(....); // Only difference
        KrbTgsRep tgs_rep = null;
        String kdc = null;
        try {
            kdc = tgs_req.send();
            tgs_rep = tgs_req.getReply();
        } catch (KrbException ke) {
            if (ke.returnCode() == Krb5.KRB_ERR_RESPONSE_TOO_BIG) {
                    // set useTCP and retry
                tgs_req.send(service.getRealmString(), kdc, true);
                tgs_rep = tgs_req.getReply();
            } else {
                throw ke;
            }
        }
        return tgs_rep.getCreds();