private String getRandomOrderId(String prefix) {
        String orderId;
        Date date = new Date();
        StringBuilder sb = new StringBuilder();
        if (prefix != null) {
            sb.append(prefix);
            sb.append("_");
        }
        SimpleDateFormat df = new SimpleDateFormat("MMkkmmssSSSS");
        sb.append(sequence.getAndIncrement());
        sb.append("_");
        sb.append(df.format(date));
        orderId = sb.toString();
        if (orderId.length() > 30) {
            orderId = orderId.substring(0, 29);
        }
        return orderId;
    }