自定义Iterator
WeekendDayIterator 是指定的Interval 中周末的Iterator:
class WeekendDayIterator(interval: Interval) extends Iterator[LocalDate] {
var day = interval.getStart.toLocalDate
private def peek = day.plusDays(1)
def hasNext: Boolean = peek.isBefore(interval.getEnd.toLocalDate)
private def isWeekend(ld: LocalDate): Boolean = ld.getDayOfWeek == SATURDAY || ld.getDayOfWeek == SUNDAY
def next(): LocalDate = { val d = day; do day = peek; while (!isWeekend(day)); d }
}
def weekendLocalDates(interval: Interval): List[LocalDate] = new WeekendDayIterator(interval).toList
// The `LocalDate`s for weekend days
println(weekendLocalDates(new Interval(new DateTime("2013-10-01"), new DateTime("2014-01-30"))))
// The days of year for weekend days
println(weekendLocalDates(new Interval(new DateTime("2013-10-01"), new DateTime("2014-01-30"))).map(_.getDayOfYear))
导致以下输出:
List(2013-10-01, 2013-10-05, 2013-10-06, 2013-10-12, 2013-10-13, 2013-10-19, 2013-10-20, 2013-10-26, 2013-10-27, 2013-11-02, 2013-11-03, 2013-11-09, 2013-11-10, 2013-11-16, 2013-11-17, 2013-11-23, 2013-11-24, 2013-11-30, 2013-12-01, 2013-12-07, 2013-12-08, 2013-12-14, 2013-12-15, 2013-12-21, 2013-12-22, 2013-12-28, 2013-12-29, 2014-01-04, 2014-01-05, 2014-01-11, 2014-01-12, 2014-01-18, 2014-01-19, 2014-01-25, 2014-01-26)
List(274, 278, 279, 285, 286, 292, 293, 299, 300, 306, 307, 313, 314, 320, 321, 327, 328, 334, 335, 341, 342, 348, 349, 355, 356, 362, 363, 4, 5, 11, 12, 18, 19, 25, 26)
代码写在Scala。将其移植到 Java 应该很简单。