在最大非零值处切断一个持续时间

Question

有没有方便的方法将持续时间d四舍五入到最重要的时间单位？

例如：

<代码>持续时间。分钟数（65）-

Duration.of分钟（1500）-




Answer 1

这里有一种方法：

// All of the ChronoUnit values that are convertible from TimeUnit values, because
// these are the only ones that can be used by Duration.of(amount, unit).
private static final ChronoUnit[] timeUnitValues =
        Arrays.stream(TimeUnit.values())
            .map(TimeUnit::toChronoUnit)
            .toArray(ChronoUnit[]::new);

public static Duration truncateToMajorUnit(Duration duration) {
    for (var unit : timeUnitValues) {
        if (duration.compareTo(Duration.of(1, unit)) > 0)
            duration = duration.truncatedTo(unit);
    }
    return duration;
}

public static void main(String[] args) {
    System.out.println(truncateToMajorUnit(Duration.ofMinutes(59)));   // 59m
    System.out.println(truncateToMajorUnit(Duration.ofMinutes(65)));   // 1h
    System.out.println(truncateToMajorUnit(Duration.ofMinutes(185)));  // 3h
    System.out.println(truncateToMajorUnit(Duration.ofMinutes(1500))); // 24h
    System.out.println(truncateToMajorUnit(Duration.ofMinutes(1800))); // still 24h
}