LocalDateTime 和 Date 相互转换，LocalDateTime获取时间戳，时间戳转LocalDateTime

LocalDateTime to Date

LocalDateTime now = LocalDateTime.now();
Date date = Date.from(now.atZone(ZoneId.systemDefault()).toInstant());

Date to LocalDateTime

Date date = new Date();
LocalDateTime now = date.toInstant().atZone(ZoneId.systemDefault()).toLocalDateTime();

LocalDateTime to Timestamp 

LocalDateTime now = LocalDateTime.now();
long l = now.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli();

Timestamp to LocalDateTime

Long l = 1581733899495L;
LocalDateTime now = LocalDateTime.ofInstant(Instant.ofEpochMilli(l),TimeZone.getDefault().toZoneId());