java 8 日期函数

1、Timestamp（long）转成日期

Timestamp timestamp = new Timestamp(System.currentTimeMillis());

    LocalDateTime localDateTime = timestamp.toLocalDateTime();//之后就可以通过java8 新API操作时间了

localDateTime.toLocalDate();

Date date = new Date(timestamp.getTime());//以前的Timetamp转日期的写法，然后通过SimpleDateFormatter转化了

2、Date与LocalDateTime的互相转换

/**
* LocalDateTime转Date
* @param localDateTime
* @return
*/
public static Date localDateTime2Date(LocalDateTime localDateTime){
ZoneId zoneId = ZoneId.systemDefault();
ZonedDateTime zonedDateTime = localDateTime.atZone(zoneId);
Date date = Date.from(zonedDateTime.toInstant());
return date;
}/**
* Date转LocalDateTime
* @param date
* @return
*/
public static LocalDateTime Date2LocalDateTime(Date date){
Instant instant = date.toInstant();
ZoneId zoneId = ZoneId.systemDefault();
LocalDateTime localDateTime = instant.atZone(zoneId).toLocalDateTime();
return localDateTime;
}