public static String formatUnixTimestamp(long unixtime, String format, TimeZone tz) {
    SimpleDateFormat formatter = FORMATTER_CACHE.get(format);
    formatter.setTimeZone(tz);
    Date date = new Date(unixtime * 1000);
    try {
      return formatter.format(date);
    } catch (Exception e) {
      LOG.error("Exception when formatting.", e);
      return null;
    }
  }
Convert unix timestamp (seconds since '1970-01-01 00:00:00' UTC) to datetime string in the
given format.
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/util/DateTimeUtils.java