将字符串转换为GregorianCalendar [英] Convert a string to GregorianCalendar

问题描述

我有一个来自电子邮件标题的字符串，例如 Date：Mon，27 Oct 2008 08:33:29 -0700 。我需要的是一个GregorianCalendar的实例，将代表相同的时刻。

I have a string from an email header, like Date: Mon, 27 Oct 2008 08:33:29 -0700. What I need is an instance of GregorianCalendar, that will represent the same moment. As easy as that -- how do I do it?

对于最快的，这是不正常工作：

And for the fastest ones -- this is not going to work properly:

SimpleDateFormat format = ... // whatever you want
Date date = format.parse(myString)
GregorianCalendar calendar = new GregorianCalendar();
calendar.setTime(date)

因为它会将时区标准化为UTC本地机器时间，取决于Java版本）。我需要的是calendar.getTimeZone（）。getRawOffset（）来返回 -7 * milisInAnHour 。

because it will normalize the timezone to UTC (or your local machine time, depending on Java version). What I need is calendar.getTimeZone().getRawOffset() to return -7 * milisInAnHour.

推荐答案

我建议查看Joda时间库，如果这是一个选项。我通常反对使用第三方库，当核心平台提供类似的功能，但我把这个例外，因为Joda时间的作者也在后面的JSR310，Joda时间基本上将滚动到Java 7最终。

I'd recommend looking into the Joda Time library, if that's an option. I'm normally against using a third-party library when the core platform provides similar functionality, but I made this an exception because the author of Joda Time is also behind JSR310, and Joda Time is basically going to be rolled into Java 7 eventually.

http://joda-time.sourceforge.net/

无论如何，如果Joda Time是一个选项，这样的应该工作：

So anyway, if Joda Time is an option, something like this should work:

DateTimeFormatter formatter =
    DateTimeFormat.forPattern("your pattern").withOffsetParsed();
DateTime dateTime = formatter.parseDateTime("your input");
GregorianCalendar cal = dateTime.toGregorianCalendar();

我希望这有助于。

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