如何防止 Joda Time 在巴西 DST 过渡期间抛出异常

Question

今天，我们的巴西用户正在为我们生成大量崩溃报告。我已经追踪到这段代码，它抛出了一个 Joda 异常：

import org.joda.time.DateTime;
import org.joda.time.DateTimeUtils;
import org.joda.time.DateTimeZone;
import org.joda.time.LocalTime;

public class ScratchSpace {

    public static void main(String[] args) {
        // force Joda to act like we are in Sao Paolo on 2015-10-18
        DateTimeUtils.setCurrentMillisFixed(1445185758078L); // 2015-10-18T18:29
        DateTimeZone.setDefault(DateTimeZone.forID("America/Sao_Paulo"));

        // most of users have offset == 0, but it could be any number of millis from 0 to 86_400_000-1 (millis in day) 
        int offset = 0;

        // local time at start of day + offset millis  
        final LocalTime localTime = LocalTime.fromMillisOfDay(offset);

        // convert to a time on the current day
        DateTime dateTime = localTime.toDateTimeToday();  // throws org.joda.time.IllegalFieldValueException exception
        System.out.println("dateTime = " + dateTime);
    }
}

例外：

Exception in thread "main" org.joda.time.IllegalFieldValueException: Value 0 for hourOfDay is not supported: Illegal instant due to time zone offset transition (daylight savings time 'gap'): 2015-10-18T00:29:18.078 (America/Sao_Paulo)
    at org.joda.time.chrono.ZonedChronology$ZonedDateTimeField.set(ZonedChronology.java:486)
    at org.joda.time.chrono.BaseChronology.set(BaseChronology.java:240)
    at org.joda.time.LocalTime.toDateTimeToday(LocalTime.java:1287)
    at org.joda.time.LocalTime.toDateTimeToday(LocalTime.java:1270)

我在 OS X 10.11 和 Joda Time 2.8.2 上使用 Java 1.8.0_60。

什么变通方法可以让我正确获得一个 DateTime 实例，该实例表示当天的时间，该时间是一天开始后偏移毫秒？

Answer 1

不要通过 LocalTime。创建一个 DateTime，并以毫秒为单位添加偏移量：

DateTime startOfDay = LocalDate.now().toDateTimeAtStartOfDay();
DateTime dateTime = startOfDay.plus(offset);

System.out.println("dateTime = " + dateTime);