Question

我正在尝试使用DateFormatSymbols查找工作日，这是一个简短的程序

String[] shortWeekdays = new DateFormatSymbols().getShortWeekdays();
        System.out.println(shortWeekdays.length);

        for (int i = 0; i < shortWeekdays.length; i++) {
            String shortWeekday = shortWeekdays[i];
            System.out.println("shortWeekday = " + shortWeekday);
        }

它正在给我一个输出

shortWeekday =

shortWeekday = Sun

shortWeekday = Mon

shortWeekday = Tue

shortWeekday = Wed

shortWeekday = Thu

shortWeekday = Fri

shortWeekday =周六

我不确定为什么它的总长度为8，而它应该给它为7

Answer 1

Calendar.{SUNDAY, MONDAY, ... SUNDAY }的值范围是1-7。 getShortWeekDays()州的文档：

返回：简短的工作日字符串。使用Calendar.SUNDAY，Calendar.MONDAY等来索引结果数组。

所以我期望一个可以用值1-7索引的数组......这意味着它必须有8个元素（因为Java中的所有数组都是基于0的）。

Answer 2

Java中的星期几是基于1的，而不是基于0的。 DateFormatSymbols类的作者明确决定他会做以下的

private void initializeData(Locale desiredLocale) {
    int i;
    ResourceBundle resource = cacheLookup(desiredLocale);

    // FIXME: cache only ResourceBundle. Hence every time, will do
    // getObject(). This won't be necessary if the Resource itself
    // is cached.
    eras = (String[])resource.getObject("Eras");
    months = resource.getStringArray("MonthNames");
    shortMonths = resource.getStringArray("MonthAbbreviations");
    String[] lWeekdays = resource.getStringArray("DayNames");
    weekdays = new String[8];
    weekdays[0] = "";  // 1-based
    for (i=0; i<lWeekdays.length; i++)
        weekdays[i+1] = lWeekdays[i];
    String[] sWeekdays = resource.getStringArray("DayAbbreviations");
    shortWeekdays = new String[8];
    shortWeekdays[0] = "";  // 1-based
/*** start of what causes your odd behaviour **/
    for (i=0; i<sWeekdays.length; i++)
        shortWeekdays[i+1] = sWeekdays[i];
    ampms = resource.getStringArray("AmPmMarkers");
    localPatternChars = resource.getString("DateTimePatternChars");

locale = desiredLocale;
}

为了使执行日查找更简单。

Answer 3

private String[] getWeekDayNames() {
            String[] names = new DateFormatSymbols().getShortWeekdays();
            List<String> daysName = new ArrayList<>(Arrays.asList(names));
            daysName.remove(0);

            //unComment bellow line if you want a start day Monday
            //daysName.add(daysName.remove(0));

            if (typedArray.getInt(noman.weekcalendar.R.styleable.WeekCalendar_dayNameLength, 0) == 0)
                for (int i = 0; i < daysName.size(); i++)
                    //(0,3 MON) (0,1 M) (comment ".substring(0,3)" for full length of the day)
                    daysName.set(i, daysName.get(i).substring(0, 3));
            names = new String[daysName.size()];
            daysName.toArray(names);
            return names;

        }

DateFormatSymbols（）。getShortWeekdays（）返回工作日计为8

3 个答案: