LocalDateTime.parse的java.time.format.DateTimeParseException

Question

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

public class TestProject {

    public static void main(String[] args) {
        String dateString = "2018-03-01T14:52:48Z";
        DateTimeFormatter dtf = DateTimeFormatter.ISO_INSTANT;
        LocalDateTime localDateTime = LocalDateTime.parse(dateString, dtf);
    }
}

投掷：

Exception in thread "main" java.time.format.DateTimeParseException: Text '2018-03-01T14:52:48Z' could not be parsed: Unable to obtain LocalDateTime from TemporalAccessor: {NanoOfSecond=0, InstantSeconds=1519915968, MilliOfSecond=0, MicroOfSecond=0},ISO of type java.time.format.Parsed
    at java.base/java.time.format.DateTimeFormatter.createError(DateTimeFormatter.java:1959)
    at java.base/java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1894)
    at java.base/java.time.LocalDateTime.parse(LocalDateTime.java:492)
    at org.bdshadow.TestProject.main(TestProject.java:11)
Caused by: java.time.DateTimeException: Unable to obtain LocalDateTime from TemporalAccessor: {NanoOfSecond=0, InstantSeconds=1519915968, MilliOfSecond=0, MicroOfSecond=0},ISO of type java.time.format.Parsed
    at java.base/java.time.LocalDateTime.from(LocalDateTime.java:461)
    at java.base/java.time.format.Parsed.query(Parsed.java:235)
    at java.base/java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1890)
    ... 2 more
Caused by: java.time.DateTimeException: Unable to obtain LocalDate from TemporalAccessor: {NanoOfSecond=0, InstantSeconds=1519915968, MilliOfSecond=0, MicroOfSecond=0},ISO of type java.time.format.Parsed
    at java.base/java.time.LocalDate.from(LocalDate.java:396)
    at java.base/java.time.LocalDateTime.from(LocalDateTime.java:456)
    ... 4 more

日期的字符串表示形式与datetimeformatter.iso_instant的javadocs中完全相同:https://docs.oracle.com/javase/8/docs/api/java/time/format/datetimeformatter.html#iso_instant。在Java9中没有改变:https://docs.oracle.com/javase/9/docs/api/java/time/format/datetimeformatter.html#iso_instant

Answer 1

我相信这是因为ISO_instant用于解析instant

正如javadoc所说：

这是一个特例格式化程序，旨在允许人类可读的java.time.instant形式。

    String dateString = "2018-03-01T14:52:48Z";
    DateTimeFormatter dtf = DateTimeFormatter.ISO_INSTANT;
    Instant instant = Instant.from(dtf.parse(dateString));

LocalDateTime localDateTime = LocalDateTime.ofInstant(instant, ZoneId.systemDefault())