get current date time timestamp java
// 2021-03-24 16:48:05.591
  Timestamp timestamp = new Timestamp(System.currentTimeMillis());
  // 2021-03-24 16:48:05.591
  Date date = new Date();
  Timestamp timestamp2 = new Timestamp(date.getTime());
  // convert Instant to Timestamp
  Timestamp ts = Timestamp.from(Instant.now())
  // convert ZonedDateTime to Instant to Timestamp
  Timestamp ts = Timestamp.from(ZonedDateTime.now().toInstant()));
  // convert Timestamp to Instant
  Instant instant = ts.toInstant();
