不是假日的上一个工作日期

Question

我有以下holiday类：

public class Holiday {

    private int day;
    private int month;


    public Holiday(GregorianCalendar calendar) {
        this.day = calendar.get(GregorianCalendar.DAY_OF_MONTH);
        this.month = calendar.get(GregorianCalendar.MONTH) + 1;
    }

}

枚举日：

public enum Day {

    SATURDAY(6), SUNDAY(7);

    private int index;

    Day(int index) {
        this.index = index;
    }

    public int getIndex() {
        return index;
    }
}


public class DateTool {

    private static final String DATE_FORMAT = "yyyy_MM_dd";

    public DateTool() {
        super();
    }


    public static String getPreviousWorkingDay(List<Holiday> listOfHolidays) {
            //derive the last working day that is not saturday/sunday
    }

    public static String parseDate(Date date) {
        return new SimpleDateFormat(DATE_FORMAT).format(date);
    }

    public static boolean isSunday(LocalDateTime date) {
        return date.getDayOfWeek().getValue() == Day.SUNDAY.getIndex();
    }

    public static boolean isSaturday(LocalDateTime date) {
        return date.getDayOfWeek().getValue() == Day.SATURDAY.getIndex();
    }

}

  if (todayIsHoliday(listOfHolidays)) {
                getPreviousWorkingDay(listOfHolidays);
            }

我不确定该如何回头看。请注意假期的列表不仅仅是周六和周日。它们是乡村节日，如中国的新年等。

我正在使用Java8，因此任何重构或改进都是受欢迎的：）

Answer 1

private static final DateTimeFormatter dateFormatter
        = DateTimeFormatter.ofPattern("uuuu_MM_dd");

public static String getPreviousWorkingDay(List<MonthDay> listOfHolidays) {
    LocalDate workingDay = LocalDate.now(ZoneId.of("Pacific/Easter")).minusDays(1);
    while (workingDay.getDayOfWeek().equals(DayOfWeek.SATURDAY) 
            || workingDay.getDayOfWeek().equals(DayOfWeek.SUNDAY)
            || listOfHolidays.contains(MonthDay.from(workingDay))) {
        workingDay = workingDay.minusDays(1);
    }
    return workingDay.format(dateFormatter);
}

我正在使用Java.time，这是现代Java日期和时间API，正如在一个注释中提到的，我建议您也这样做。让我们看看上面的方法在行动：

    System.out.println(getPreviousWorkingDay(Collections.emptyList()));
    // Let’s say Valentin’s day is a holiday
    System.out.println(getPreviousWorkingDay(List.of(MonthDay.of(Month.FEBRUARY, 14))));
    // And so are Lent Monday and the death day of Danish would-be king Henrik 
    System.out.println(getPreviousWorkingDay(List.of(MonthDay.of(Month.FEBRUARY, 12), 
            MonthDay.of(Month.FEBRUARY, 13), MonthDay.of(Month.FEBRUARY, 14))));

今本印曰：

2018_02_14
2018_02_13
2018_02_09

（我有点作弊了，因为每年的四旬斋星期一都不是同一天；但我觉得不需要把这样的假期考虑在内。）

链接：Oracle教程：日期时间说明如何使用java.Time。