将字符串解析为本地日期时间

Question

将字符串解析为本地日期时间时遇到一个奇怪的问题

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class Main {

    public static void main(String args[])
    {
        DateTimeFormatter formatter = DateTimeFormatter.ISO_LOCAL_TIME;
         LocalDateTime.parse("00:00",formatter);
    }

}

给我：

Exception in thread "main" java.time.format.DateTimeParseException: Text '00:00' could not be parsed: Unable to obtain LocalDateTime from TemporalAccessor: {},ISO resolved to 00:00 of type java.time.format.Parsed
    at java.time.format.DateTimeFormatter.createError(Unknown Source)
    at java.time.format.DateTimeFormatter.parse(Unknown Source)
    at java.time.LocalDateTime.parse(Unknown Source)
    at Main.main(Main.java:9)
Caused by: java.time.DateTimeException: Unable to obtain LocalDateTime from TemporalAccessor: {},ISO resolved to 00:00 of type java.time.format.Parsed
    at java.time.LocalDateTime.from(Unknown Source)
    at java.time.format.Parsed.query(Unknown Source)
    ... 3 more
Caused by: java.time.DateTimeException: Unable to obtain LocalDate from TemporalAccessor: {},ISO resolved to 00:00 of type java.time.format.Parsed
    at java.time.LocalDate.from(Unknown Source)
    ... 5 more

我想将格式为“小时：分钟”的字符串解析为本地日期时间（24 小时格式）。我不在乎分配什么月/年/日，我只想要时间。

Answer 1

我不在乎分配什么月/年/日，我只想要时间。

这表明您应该将其解析为LocalTime，因为这是字符串实际表示的内容。然后，您可以添加任何LocalDate 以获取LocalDateTime，如果您真的想假装您有更多信息，那么您有：

import java.time.*;
import java.time.format.*;

public class Test {    
    public static void main(String args[]) {
        DateTimeFormatter formatter = DateTimeFormatter.ISO_LOCAL_TIME;
        LocalTime time = LocalTime.parse("00:00",formatter);
        LocalDate date = LocalDate.of(2000, 1, 1);
        LocalDateTime dateTime = date.atTime(time);
        System.out.println(dateTime); // 2000-01-01T00:00
    }
}

如果您可以完全避免创建LocalDateTime 而只使用LocalTime，那就更好了。