两个时区之间的总飞行时间？

Question

如果我们在14:05离开法兰克福,并在16:40到达洛杉矶.飞多长时间？

我试过以下:

ZoneId frank = ZoneId.of("Europe/Berlin");
ZoneId los = ZoneId.of("America/Los_Angeles");

LocalDateTime dateTime = LocalDateTime.of(2015, 02, 20, 14, 05);
LocalDateTime dateTime2 = LocalDateTime.of(2015, 02, 20, 16, 40);

ZonedDateTime berlinDateTime = ZonedDateTime.of(dateTime, frank);
ZonedDateTime losDateTime2 = ZonedDateTime.of(dateTime2, los);

int offsetInSeconds = berlinDateTime.getOffset().getTotalSeconds();
int offsetInSeconds2 = losDateTime2.getOffset().getTotalSeconds();

Duration duration = Duration.ofSeconds(offsetInSeconds - offsetInSeconds2);
System.out.println(duration);

但我无法得到大约11小时30分钟的成功答案.有人请帮助我弄清楚上面的问题.谢谢 :)

Answer 1

getOffset是错误的方法.这将获得该区域在该时间点的UTC偏移量.它无助于确定一天中的实际时间.

一种方法是使用明确获取Instant每个值表示的toInstant.然后Duration.between用来计算经过的时间.

Instant departingInstant = berlinDateTime.toInstant();
Instant arrivingInstant = losDateTime2.toInstant();
Duration duration = Duration.between(departingInstant, arrivingInstant);

另外,由于Duration.between对作品Temporal的对象,都Instant和ZonedDateTime实施Temporal,你可以打电话Duration.between直接在ZonedDateTime对象:

Duration duration = Duration.between(berlinDateTime, losDateTime2);

最后,如果您希望直接获得一个度量单位(例如总秒数),那么像atao提到的那些快捷方式就可以了.任何这些都是可以接受的.

Answer 2

更换:

int offsetInSeconds = berlinDateTime.getOffset().getTotalSeconds();
int offsetInSeconds2 = losDateTime2.getOffset().getTotalSeconds();

Duration duration = Duration.ofSeconds(offsetInSeconds - offsetInSeconds2);

有:

long seconds = ChronoUnit.SECONDS.between(berlinDateTime, losDateTime2);
Duration duration = Duration.ofSeconds(seconds);

编辑

我喜欢Matt Johnson给出的更短(也是最短)的答案:

Duration duration = Duration.between(berlinDateTime, losDateTime2);