1、使用LocalDateTime架包

 LocalDate localDate = LocalDate.now();
 Timestamp timestamp= Timestamp.valueOf(LocalDateTime.now());
 System.out.println(timestamp.getTime());

结果是

2、使用Instant架包

Instant instant = Instant.now();
long timeStampMillis = instant.toEpochMilli();
System.out.println(timeStampMillis);

结果是