Timstamp转string set后面该怎么写

 String cotractBdate="2022-01-19 09:11:52";
        BigDecimal bigDecimal = new BigDecimal(sg);
            SimpleDateFormat dateFormate = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
          Date date =dateFormate.parse(cotractBdate);
        Timestamp timestamp = new Timestamp(date.getTime());