如何在 Java 中获取 UTC 或 GMT 的当前日期和时间?

When I create a new Date object, it is initialized to the current time but in the local timezone. How can I get the current date and time in GMT?

解决方案

java.util.Date has no specific time zone, although its value is most commonly thought of in relation to UTC. What makes you think it's in local time?

To be precise: the value within a java.util.Date is the number of milliseconds since the Unix epoch, which occurred at midnight January 1st 1970, UTC. The same epoch could also be described in other time zones, but the traditional description is in terms of UTC. As it's a number of milliseconds since a fixed epoch, the value within java.util.Date is the same around the world at any particular instant, regardless of local time zone.

I suspect the problem is that you're displaying it via an instance of Calendar which uses the local timezone, or possibly using Date.toString() which also uses the local timezone, or a SimpleDateFormat instance, which, by default, also uses local timezone.

If this isn't the problem, please post some sample code.

I would, however, recommend that you use Joda-Time anyway, which offers a much clearer API.