使用DateTimeFormatterBuilder将字符串解析为LocalDateTime时如何防止自动生成的"T"字母 [英] How to prevent auto-generated 'T' letter when parsing String to LocalDateTime using DateTimeFormatterBuilder

问题描述

我有这段代码，可以将String双向解析为LocalDateTime:

I have this fragment of code to bidirectional parsing String to LocalDateTime:

public class ConvertLocalDateToString {

private static final DateTimeFormatter CUSTOM_LOCAL_DATE;
static {
    CUSTOM_LOCAL_DATE = new DateTimeFormatterBuilder()
            .appendValue(YEAR, 4, 10, SignStyle.EXCEEDS_PAD)
            .appendLiteral('-')
            .appendValue(MONTH_OF_YEAR, 2)
            .appendLiteral('-')
            .appendValue(DAY_OF_MONTH, 2)
            .appendLiteral(' ')
            .appendValue(HOUR_OF_DAY, 2)
            .appendLiteral(':')
            .appendValue(MINUTE_OF_HOUR, 2)
            .optionalStart()
            .appendLiteral(':')
            .appendValue(SECOND_OF_MINUTE, 2)
            .toFormatter();
}

public static void main(String[] args) {

    String str = "2020-02-18 15:04:30";
    LocalDateTime dateTime = LocalDateTime.parse(str, CUSTOM_LOCAL_DATE); //2020-02-18T15:04:30

    LocalDateTime addedDateTime = LocalDateTime.parse(dateTime.plusHours(10).format(CUSTOM_LOCAL_DATE.withZone(ZoneOffset.UTC)));
    System.out.println(addedDateTime);
    System.out.println(dateTime); //2020-02-18T15:04:30

}

我的假设是'T'字母是由ISO-8601格式自动生成的.这导致:

My assumption is 'T' letter is auto-generated by ISO-8601 format. This caused:

DateTimeParseException:无法在索引10处解析文本'2020-02-18 15:04:30'

DateTimeParseException: Text '2020-02-18 15:04:30' could not be parsed at index 10

我如何摆脱它?

推荐答案

System.out.println(dateTime)与System.out.println(String.valueOf(dateTime))相同.

String.valueOf(dateTime)与dateTime.toString()相同，不同之处在于它可以处理null值.

String.valueOf(dateTime) is the same as dateTime.toString(), except it can handle null value.

在LocalDateTime上调用toString()是

Calling toString() on a LocalDateTime is documented to do this:

将此日期时间输出为字符串，例如2007-12-03T10:15:30.

输出将是以下ISO-8601格式之一:

The output will be one of the following ISO-8601 formats:

• uuuu-MM-dd'T'HH:mm
• uuuu-MM-dd'T'HH:mm:ss
• uuuu-MM-dd'T'HH:mm:ss.SSS
• uuuu-MM-dd'T'HH:mm:ss.SSSSSS
• uuuu-MM-dd'T'HH:mm:ss.SSSSSSSSS

使用的格式将是最短的格式，用于输出被省略部分隐含为零的时间的完整值.

The format used will be the shortest that outputs the full value of the time where the omitted parts are implied to be zero.

如果要使用其他格式，请调用

If you want different format, call format(DateTimeFormatter formatter).

因此，回答您的问题:

我的假设是'T'字母由ISO-8601格式自动生成.

T不会比-和:字符自动生成.

The T is no more auto-generated than the - and : characters.

我如何摆脱它?

致电format(...)并指定所需的格式，例如

Call format(...) and specify the format you want, e.g.

System.out.println(dateTime.format(DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss")));

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