Java 8日期-时间解析，可选2-4年组件[重复]

Question

        public static LocalDate parseDateString(String date) {
            DateTimeFormatter optionalFullYearParser = java.time.format.DateTimeFormatter.ofPattern("[dd-MM-yy][dd-MM-yyyy]");
            DateTimeFormatter parser = new DateTimeFormatterBuilder()
                    .appendOptional(optionalFullYearParser)
                    .appendValueReduced(ChronoField.YEAR, 2, 4, 1900)
                    .toFormatter(new Locale ("nl","NL"));

            return java.time.LocalDate.parse(date,parser);
        }

        System.out.println(parseDateString("11-10-56").toString());
        System.out.println(parseDateString("11-10-1956").toString());
        System.out.println(parseDateString("08-05-51").toString());

Answer 1

不需要2个格式化程序对象来完成此操作，并且在使用AppendValuerEduced添加年份部分时，不应该在模式文本中包含年份部分。

public static LocalDate parseDateString(String date) {
    DateTimeFormatter parser = new DateTimeFormatterBuilder()
            .appendPattern("dd-MM-")
            .appendValueReduced(ChronoField.YEAR, 2, 4, 1900)
            .toFormatter(Locale.forLanguageTag("nl-NL"));
    return java.time.LocalDate.parse(date, parser);
}

测试

System.out.println(parseDateString("11-10-56").toString());
System.out.println(parseDateString("11-10-1956").toString());
System.out.println(parseDateString("08-05-51").toString());

输出

1956-10-11
1956-10-11
1951-05-08