在Java中将Month String转换为Integer

Question

给出一个月份字符串,例如:

    "Feb"
or
    "February"

是否有任何核心Java或第三方库功能允许您以区域设置无关的方式将此字符串转换为相应的月份数？

Answer 1

您可以使用SimpleDateFormat解析月份:

    Date date = new SimpleDateFormat("MMM", Locale.ENGLISH).parse("Feb");
    Calendar cal = Calendar.getInstance();
    cal.setTime(date);
    int month = cal.get(Calendar.MONTH);
    System.out.println(month == Calendar.FEBRUARY);

小心比较int month为int(它不等于2!).最安全的是使用Calendar静态字段(比如Calendar.FEBRUARY)来比较它们.

Answer 2

使用Joda时间的SimpleDateFormat的替代方法:

    import org.joda.time.DateTime;
    import org.joda.time.format.DateTimeFormat;
    import org.joda.time.format.DateTimeFormatter;
    ...

    // if default locale is ok simply omit '.withLocale(...)'
    DateTimeFormatter format = DateTimeFormat.forPattern("MMM");
    DateTime instance        = format.withLocale(Locale.FRENCH).parseDateTime("août");  

    int month_number         = instance.getMonthOfYear();
    String month_text        = instance.monthOfYear().getAsText(Locale.ENGLISH);

    System.out.println( "Month Number: " + month_number );
    System.out.println( "Month Text:   " + month_text   );

    OUTPUT:
        Month Number: 8
        Month Text:   August

Answer 3

Java 8解决方案：

DateTimeFormatter parser = DateTimeFormatter.ofPattern("MMM")
                                            .withLocale(Locale.ENGLISH);
TemporalAccessor accessor = parser.parse("Feb");
System.out.println(accessor.get(ChronoField.MONTH_OF_YEAR));  // prints 2