java8 时态调节器的使用（例如某月的最后一个星期天）

        LocalDate date = LocalDate.of(2000, Month.OCTOBER, 15);
        DayOfWeek dotw = date.getDayOfWeek();
        System.out.printf("%s is on a %s%n", date, dotw);//这一天是周几？
        System.out.printf("first day of Month: %s%n", date.with(TemporalAdjusters.firstDayOfMonth()));
        System.out.printf("first Monday of Month: %s%n", date.with(TemporalAdjusters.firstInMonth(DayOfWeek.MONDAY)));
        System.out.printf("last day of Month: %s%n", date.with(TemporalAdjusters.lastDayOfMonth()));
        System.out.printf("first day of next Month: %s%n", date.with(TemporalAdjusters.firstDayOfNextMonth()));
        System.out.printf("first day of next Year: %s%n", date.with(TemporalAdjusters.firstDayOfNextYear()));
        System.out.printf("first day of Year: %s%n", date.with(TemporalAdjusters.firstDayOfYear()));

自定义调节器

/**
 * The adjustInto method accepts a Temporal instance 
 * and returns an adjusted LocalDate. If the passed in
 * parameter is not a LocalDate, then a DateTimeException is thrown.
 */
public Temporal adjustInto(Temporal input) {
    LocalDate date = LocalDate.from(input);
    int day;
    if (date.getDayOfMonth() < 15) {
        day = 15;
    } else {
        day = date.with(TemporalAdjusters.lastDayOfMonth()).getDayOfMonth();
    }
    date = date.withDayOfMonth(day);
    if (date.getDayOfWeek() == DayOfWeek.SATURDAY ||
        date.getDayOfWeek() == DayOfWeek.SUNDAY) {
        date = date.with(TemporalAdjusters.previous(DayOfWeek.FRIDAY));
    }
    return input.with(date);
}