毫秒未出现在DateFormat.format输出中 [英] Milliseconds not appearing in DateFormat.format output

问题描述

我想要一个日期时间字符串，格式为 yyyy-MM-dd’T’HH：mm：ss.SSSZ。
我编写了以下代码段：

I want to have a date-time string in the "yyyy-MM-dd'T'HH:mm:ss.SSSZ" format. I wrote the following code snippet:

    Date date=Calendar.getInstance().getTime();
    String currentDateTimeString = (String) android.text.format.DateFormat.
           format("yyyy-MM-dd'T'HH:mm:ss.SSSZ",Calendar.getInstance().getTime());

但是我得到的字符串是

"2019-11-08T13:39:33.SSSZ"

格式为 yyyy-MM-dd'T'HH：mm：ss.SSS'Z'（转义'Z'）时也是如此。

also when the format is "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'" (with 'Z' escaped).

在 https://developer.android.com/reference/java/中找到text / SimpleDateFormat.html＃examples

为什么不显示毫秒？

推荐答案

我对Android开发一无所知，但是快速搜索文档可能会为您提供答案：

I know little about Android development, but a quick search in the documentation may give you the answer:

https://developer.android.com/reference/android/text/format/DateFormat

此类中的format方法实现了Unicode UTS＃35模式的子集。此类当前支持的子集包含以下格式字符：acdEHhLKkLMmsyz。直到API级别17，仅支持adEhkMmszy。请注意，此类为了向后兼容而错误地将k当作H来实现。

The format methods in this class implement a subset of Unicode UTS #35 patterns. The subset currently supported by this class includes the following format characters: acdEHhLKkLMmsyz. Up to API level 17, only adEhkMmszy were supported. Note that this class incorrectly implements k as if it were H for backwards compatibility.

Unicode UTS＃35没说毫秒。 b $ b https://unicode.org/reports/tr35/tr35-dates .html＃Date_Format_Patterns

The Unicode UTS #35 says nothing about milliseconds: https://unicode.org/reports/tr35/tr35-dates.html#Date_Format_Patterns

所以似乎不支持格式毫秒设置。

So it seems that formatting milliseconds is not supported.

而是使用Java标准类 LocalDateTime 和 DateTimeFormatter 来支持毫秒。

I would rather use the Java standard classes LocalDateTime and DateTimeFormatter, which do support milliseconds.

https://developer.android.com/ reference / java / time / format / DateTimeFormatter.html

[已编辑]

重新输入后阅读问题，我认为问题是您使用的是 DateFormat 而不是 SimpleDateFormat 。您提供的链接与您在代码中使用的实际课程不符。

After re-reading the question, I think the problem is that you're using DateFormat instead of SimpleDateFormat. The link you've provided does not correspond with the actual class you're using in your code.

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