java - UTC 的 Joda DateTime getMillis() 不正确，而是返回本地毫秒

Question

我正在尝试获取 UTC 毫秒以转换 Joda DateTime instance到 SQL Timestamp ，但是它正在将其转换为我的本地时间。

这是一个例子:

DateTime d = DateTime.now().withZone(DateTimeZone.UTC);
Timestamp t = new Timestamp(d.getMillis());
System.out.println(t);
t.setHours(d.getHourOfDay());
System.out.println(t);

输出:

2015-04-17 18:11:27.277
2015-04-17 22:11:27.277

为什么会转换为我本地的时区？我以为 DateTime.getMillis() 方法总是返回 UTC 的毫秒数？

Answer 1

当您更改时间时，您不会更改自纪元以来的毫秒数。换句话说，调用 withZone 实际上并没有改变底层的 long millis。

真正的问题是 Timestamp.setHours 方法，该方法自 Java 1.1 以来已被弃用。请参阅文档:

@Deprecated

public void setHours(int hours)

Deprecated. As of JDK version 1.1, replaced by Calendar.set(Calendar.HOUR_OF_DAY, int hours). Sets the hour of this Date object to the specified value. This Date object is modified so that it represents a point in time within the specified hour of the day, with the year, month, date, minute, and second the same as before, as interpreted in the local time zone.