我怎样才能在java中找到最大值

Question

    try {
        ResultSet r = JDBC.getdata("SELECT MAX(TransactionID) from transaction");
        while (r.next()) {
            int l = r.getInt(1);

            int inid = l + 1;
            lbNewTransactionID.setText(new Integer(inid).toString());

        }
    } catch (Exception e) {
        e.printStackTrace();
    }

当我使用它时，不能产生超过10个数字