public TTransport createClientTransport()

in kyuubi-relocated-hive-metastore-client/src/main/java/org/apache/kyuubi/shaded/hive/metastore/security/HadoopThriftAuthBridge.java [89:153]
62 lines of code
6 McCabe index (conditional complexity)

    public TTransport createClientTransport(
        String principalConfig,
        String host,
        String methodStr,
        String tokenStrForm,
        final TTransport underlyingTransport,
        final Map<String, String> saslProps)
        throws IOException {
      final AuthMethod method = AuthMethod.valueOf(AuthMethod.class, methodStr);

      TTransport saslTransport = null;
      switch (method) {
        case DIGEST:
          Token<DelegationTokenIdentifier> t = new Token<>();
          t.decodeFromUrlString(tokenStrForm);
          try {
            saslTransport =
                new TSaslClientTransport(
                    method.getMechanismName(),
                    null,
                    null,
                    SaslRpcServer.SASL_DEFAULT_REALM,
                    saslProps,
                    new SaslClientCallbackHandler(t),
                    underlyingTransport);
          } catch (TTransportException e) {
            e.printStackTrace();
          }
          return new TUGIAssumingTransport(saslTransport, UserGroupInformation.getCurrentUser());

        case KERBEROS:
          String serverPrincipal = SecurityUtil.getServerPrincipal(principalConfig, host);
          final String names[] = SaslRpcServer.splitKerberosName(serverPrincipal);
          if (names.length != 3) {
            throw new IOException(
                "Kerberos principal name does NOT have the expected hostname part: "
                    + serverPrincipal);
          }
          try {
            return UserGroupInformation.getCurrentUser()
                .doAs(
                    new PrivilegedExceptionAction<TUGIAssumingTransport>() {
                      @Override
                      public TUGIAssumingTransport run() throws IOException, TTransportException {
                        TTransport saslTransport =
                            new TSaslClientTransport(
                                method.getMechanismName(),
                                null,
                                names[0],
                                names[1],
                                saslProps,
                                null,
                                underlyingTransport);
                        return new TUGIAssumingTransport(
                            saslTransport, UserGroupInformation.getCurrentUser());
                      }
                    });
          } catch (InterruptedException | SaslException se) {
            throw new IOException("Could not instantiate SASL transport", se);
          }

        default:
          throw new IOException("Unsupported authentication method: " + method);
      }
    }