java - 获取一年的日期的Util

Question

我有一个表，我希望其中的每一行都表示为一个日期，以及一些其他列来表示该特定日期的特征。所以，基本上我一年会有 365 行。我需要用 Java 编写一个批处理作业，我将通过休息端点触发该作业。我会将特定年份传递给 Controller ​​(例如 2020)。然后，我想要一种方法，它可以让我获得 2020 年的所有 366 天(因为 2020 年是闰年)以及周末(周六/周日)或工作日(周一至周五)。

我稍后会批量插入这 366 天的数据库。

有人可以帮我写这个实用方法吗？

Answer 1

要接收给定年份的日期列表，您可以使用 java.time 创建如下方法:

public static List<LocalDate> getDaysOfYear(int year) {
    // initialize a list of LocalDate
    List<LocalDate> yearDates = new ArrayList<>();
    /*
     * create a year object from the argument
     * to reliably get the amount of days that year has
     */
    Year thatYear = Year.of(year);
    // then just add a LocalDate per day of that year to the list
    for (int dayOfYear = 1; dayOfYear <= thatYear.length(); dayOfYear++) {
        yearDates.add(LocalDate.ofYearDay(year, dayOfYear));
    }
    // and return the list
    return yearDates;
}

您可以使用结果来提取每天的信息(例如在 main 中):

public static void main(String[] args) {
    // receive the LocalDates of a given year
    List<LocalDate> yearDates = getDaysOfYear(2020);
    // define a locale for output (language, formats and so on)
    Locale localeToBeUsed = Locale.US;
    
    // then extract information about each date
    for (LocalDate date : yearDates) {
        // or extract the desired parts, like the day of week
        DayOfWeek dayOfWeek = date.getDayOfWeek();
        // the month
        Month month = date.getMonth();
        // the calendar week based on a locale (the one of your system here)
        WeekFields weekFields = WeekFields.of(localeToBeUsed);
        int calendarWeek = date.get(weekFields.weekOfWeekBasedYear());
        // and print the concatenated information (formatted, depending on the locale)
        System.out.println(date.format(DateTimeFormatter.ofPattern("uuuu-MM-dd",
                                                                    localeToBeUsed))
                + ", " + dayOfWeek.getDisplayName(TextStyle.FULL, localeToBeUsed)
                + ", CW " + calendarWeek
                + ", " + month.getDisplayName(TextStyle.FULL, localeToBeUsed));
    }
}

输出将如下所示(为了简洁起见，仅显示一些行):

2020-01-01, Wednesday, CW 1, January
...
2020-02-29, Saturday, CW 9, February
...
2020-05-08, Friday, CW 19, May
...
2020-12-31, Thursday, CW 1, December