Call Java class with variable in groovy

Yes I have source code whole java class. 

public final class TicketTestUtil {

    private static final Gson gson = JsonUtils.createGson(false);
    private static final String HMAC_PASSWORD_IN_BASE64 = "xxxxxxxxx";

    private TicketTestUtil() {
        // empty on purpose for utility class
    }

    public static String generateTicketJson() {
        Ticket ticket = generateTicket();
        return gson.toJson(ticket);
    }

    public static Ticket generateTicket() {

        RandomStringGenerator randomStringGenerator = new SecuredRandomStringGenerator(SecuredRandomStringGenerator.Alphabet.ALPHANUMERIC_CHARS);

        Ticket ticket = new Ticket();
        ticket.setChannel(1l);
        ticket.setAlgorithmType(1l);
        ticket.setMethodType(1l);
        ticket.setTicketNonce(randomStringGenerator.nextString(20).toString());
        ticket.setOliNumber("4778077007");
        ticket.setTicketTimeStamp(new LocalDateTime(DateTimeZone.UTC).toDateTime(DateTimeZone.UTC).getMillis());
        ticket.setTicketVersion(1l);
        ticket.setClientThreadId(1l);

        ByteSource hmacPassword;
        try {
            hmacPassword = ByteSourceFactory.create(new Base64Codec().decode(HMAC_PASSWORD_IN_BASE64.getBytes(StandardCharsets.UTF_8)));
        } catch (CodecException e) {
            return null;
        }

        HMACHashFunction hmacHash = new HMACHashFunction(HMAC_SHA256, hmacPassword);
        String hmac = "";
        try {
            hmac = hmacHash.computeHash(ByteSourceFactory.create(ticket.getOliNumber() +
                    ticket.getChannel() +
                    ticket.getTicketNonce() +
                    ticket.getTicketTimeStamp() +
                    String.valueOf(ticket.getMethodType()))).toBase64();

        } catch (HashException e) {
            // error not logged, we don"t care
        }
        ticket.setHmac(hmac);

        return ticket;
    }

}

In the static generateTicket() is setOliNumber and there I need to set variable waht will I send from groovy in soapUI.