public static LocalDateTime toLocalDateTime(long timestamp) {
    int date = (int) (timestamp / MILLIS_PER_DAY);
    int time = (int) (timestamp % MILLIS_PER_DAY);
    if (time < 0) {
      --date;
      time += MILLIS_PER_DAY;
    }
    LocalDate localDate = toLocalDate(date);
    LocalTime localTime = toLocalTime(time);
    return LocalDateTime.of(localDate, localTime);
  }
Converts the Java type used for UDF parameters of SQL TIMESTAMP type ({@link Timestamp}) to
internal representation (long).

<p>Converse of {@link #toSQLTimestamp(long)}.
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/util/DateTimeUtils.java