如何从Java中的纪元（1970-01-01）获得毫秒？

I need to get the number of milliseconds from 1970-01-01 UTC until now UTC in Java.

我需要从1970-01-01 UTC到现在的UTC中获得UTC的毫秒数。

I would also like to be able to get the number of milliseconds from 1970-01-01 UTC to any other UTC date time.

我还希望能够获得从1970-01-01 UTC到任何其他UTC日期时间的毫秒数。

3 个解决方案

#1

How about System.currentTimeMillis()?

System.currentTimeMillis（）怎么样？

From the JavaDoc:

来自JavaDoc：

Returns: the difference, measured in milliseconds, between the current time and midnight, January 1, 1970 UTC

返回：当前时间与UTC时间1970年1月1日午夜之间的差异（以毫秒为单位）

Java 8 introduces the java.time framework, particularly the Instant class which "...models a ... point on the time-line...":

Java 8引入了java.time框架，特别是“......在时间线上模拟...点......”的Instant类：

long now = Instant.now().toEpochMilli();

Returns: the number of milliseconds since the epoch of 1970-01-01T00:00:00Z -- i.e. pretty much the same as above :-)

返回：自1970-01-01T00：00：00Z时代以来的毫秒数 - 即与上述几乎相同:-)

Cheers,

干杯，

#2

java.time

Using the java.time framework built into Java 8 and later.

使用Java 8及更高版本中内置的java.time框架。

import java.time.Instant;

Instant.now().toEpochMilli(); //Long = 1450879900184
Instant.now().getEpochSecond(); //Long = 1450879900

This works in UTC because Instant.now() is really call to Clock.systemUTC().instant()

这在UTC中有效，因为Instant.now（）实际上是对Clock.systemUTC（）的调用。

https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html

https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html

#3

Also try System.currentTimeMillis()

也试试System.currentTimeMillis（）