datetime - 使用埃塞俄比亚年表格式化 Joda Time 不显示月份名称

Question

我正在使用 Joda 时间将格里高利历日期和时间转换为埃塞俄比亚纪年法，并尝试将其格式化为“MMMM dd, yyyy”格式。我希望日期显示为“Meskerem 01, 2007”而不是“1 01, 2007”。这是 Joda 时间的错误还是我做错了什么？

DateTimeFormatter dtf = DateTimeFormat.forPattern("MMMM dd, yyyy")
Date time myDate = new DateTime(2014,9,11,0,0,0,0).withChronology(EthiopicChronology.getInstance()).toString(dtf)

Answer 1

嗯，JodaTime在国际化方面一直做的不好，sorry。但我会提出一个解决方法。

DateTimePrinter printer =
        new DateTimePrinter() {

    @Override
    public int estimatePrintedLength() {
        return 8; // type the maximum chars you need for printing ethiopic months
    }

    @Override
    public void printTo(StringBuffer buf, ReadablePartial partial, Locale locale) {
        int index = LocalDate.now().indexOf(DateTimeFieldType.monthOfYear());
        int month = partial.getValue(index);
        print(buf, month);
    }

    @Override
    public void printTo(Writer out, ReadablePartial partial, Locale locale)
        throws IOException
    {
        StringBuffer sb = new StringBuffer();
        printTo(sb, partial, locale);
        out.write(sb.toString());
    }

    @Override
    public void printTo(
        StringBuffer buf,
        long         instant,
        Chronology   chrono,
        int          displayOffset,
        DateTimeZone displayZone,
        Locale       locale
    ) {
        LocalDate date = new LocalDate(instant, EthiopicChronology.getInstance());
        print(buf, date.getMonthOfYear());
    }

    @Override
    public void printTo(
        Writer       out,
        long         instant,
        Chronology   chrono,
        int          displayOffset,
        DateTimeZone displayZone,
        Locale       locale
    ) throws IOException
    {
        StringBuffer sb = new StringBuffer();
        printTo(sb, instant, chrono, displayOffset, displayZone, locale);
        out.write(sb.toString());
    }

    private void print(StringBuffer buf, int month) {
        switch (month) {
            case 1 : // attention: ethiopic month index
                buf.append("Meskerem");
                break;
            // case 2: etc.
            default :
                buf.append(month);
        }
    }
};

DateTimeFormatter dtf =
    new DateTimeFormatterBuilder().append(printer).appendPattern(" dd, yyyy").toFormatter();
Chronology chronology = EthiopicChronology.getInstance();
DateTime ethiopic = new DateTime(2014, 9, 11, 0, 0, 0).withChronology(chronology);
String myDate = ethiopic.toString(dtf);
System.out.println(ethiopic); // 2007-01-01T00:00:00.000+02:00 (ethiopic month number and year and day-of-month!!!)
System.out.println(myDate); // Meskerem 01, 2007

请注意:此代码(如@Opal 所建议的那样？)对我不起作用:

Chronology chronology = EthiopicChronology.getInstance();
DateTimeFormatter dtf =
    DateTimeFormat.forPattern("MMMM dd, yyyy").withChronology(chronology);
String myDate = new DateTime(2014, 9, 11, 0, 0, 0).toString(dtf2);
System.out.println(myDate); // 1 01, 2007

原因是 Joda-Time 不管理自己的非公历年表的文本资源这一可悲的事实，也比较这个 SO-post .您还可以按照该帖子中的建议使用专门的字段实现。在这里，我提出了一个使用 DateTimePrinter 的解决方案，您必须在其中添加所需的缺失月份名称。