如何在 Java 中解析没有日期的月份和年份

发布于05月03日

我是这样试的

public LocalDate parseDate(String date) {
    return LocalDate.parse(date, DateTimeFormatter.ofPattern("MM-yyyy"));
}

但这段代码引发了一个异常

java.time.DateTimeException: Unable to obtain LocalDate from TemporalAccessor: {MonthOfYear=5, Year=2022},ISO of type java.time.format.Parsed

`YearMonth`

你不能创建一个LocalDate，它只需要一个月中的一天(并且不提供任何默认值).

由于您试图解析"MM-uuuu"格式的String，我假设您对创建LocalDate不感兴趣，这不可避免地归结为使用java.time.YearMonth.

例子:

public static void main(String[] args) {
    // an arbitrary mont of year
    String strMay2022 = "05-2022";
    // prepare the formatter in order to parse it
    DateTimeFormatter ymDtf = DateTimeFormatter.ofPattern("MM-uuuu");
    // then parse it to a YearMonth
    YearMonth may2022 = YearMonth.parse(strMay2022, ymDtf);
    // if necessary, define the day of that YearMonth to get a LocalDate
    LocalDate may1st2022 = may2022.atDay(1);
    // print something meaningful concerning the topic…
    System.out.println(may1st2022 + " is the first day of " + may2022);
}

输出: