如何将LocalDateTime对象转换为包括时区的ISO字符串？

LocalDateTime是偏移量/时区不可知类。你需要OffsetDateTime上课。

字符串-> OffsetDateTime

val actual = OffsetDateTime.parse("2016-12-27T08:15:05.674+01:00", DateTimeFormatter.ISO_DATE_TIME)
val expected = OffsetDateTime.of(2016, 12, 27, 8, 15, 5, 674000000, ZoneOffset.of("+01:00"))
assertThat(actual).isEqualTo(expected)

OffsetDateTime->字符串

val dateTime = OffsetDateTime.of(2016, 12, 27, 8, 15, 5, 674000000, ZoneOffset.of("+01:00"))
val actual  = dateTime.format(DateTimeFormatter.ISO_DATE_TIME)
assertThat(actual).isEqualTo("2016-12-27T08:15:05.674+01:00")