# 简要说明
```java
LocalDateTime
.parse( 
    "20230622233803466" , 
    DateTimeFormatter.ofPattern ( "uuuuMMddHHmmssSSS" ) 
)
.toString()
.replace( "T" , " " )

String input = "20230622233803466";
DateTimeFormatter f = DateTimeFormatter.ofPattern ( "uuuuMMddHHmmssSSS" );

LocalDateTime ldt = LocalDateTime.parse( input , f ) ;

String iso8601 = ldt.toString() ; 

String output = iso8601.replace( "T" , " " ) ;

ZoneId z = ZoneId.of( "Europe/London" ) ;
ZonedDateTime zdt = ldt.atZone( z ) ;

<details>
<summary>英文:</summary>
# tl;dr
    LocalDateTime
    .parse( 
        &quot;20230622233803466&quot; , 
        DateTimeFormatter.ofPattern ( &quot;uuuuMMddHHmmssSSS&quot; ) 
    )
    .toString()
    .replace( &quot;T&quot; , &quot; &quot; )
&gt;2023-06-22 23:38:03.466
# Details
You are using terrible legacy date-time classes were years ago supplanted by the modern java.time classes defined in JSR 310. Always use *java.time* classes for your date-time handling.
# *java.time* classes
I assume your example input string `&quot;2023062223380346&quot;` is a typo, as it is missing a digit on the end when compared to your desired output `2023-06-22 23:38:03:466`. 
Define a formatting pattern to match your input.
    String input = &quot;20230622233803466&quot;;
    DateTimeFormatter f = DateTimeFormatter.ofPattern ( &quot;uuuuMMddHHmmssSSS&quot; );
Parse as a `LocalDateTime`, a date with time of day but lacking the context of a time zone or offset-from-UTC.
    LocalDateTime ldt = LocalDateTime.parse( input , f ) ;
Generate text in standard ISO 8601 format.
    String iso8601 = ldt.toString() ; 
Replace the `T` in the middle with a SPACE, per your desired output.
    String output = iso8601.replace( &quot;T&quot; , &quot; &quot; ) ;
See this code [run at Ideone.com][1].
&gt;iso8601 = 2023-06-22T23:38:03.466
&gt;
&gt;output = 2023-06-22 23:38:03.466
Apparently you want to interpret this as representing a moment in a specific time zone. Use time zone names rather than assuming an offset. Offsets can vary for different periods of time — that is the definition of a time zone, a named history of the past, present, and future changes to the offset used by the people of a particular region as decided by their politicians.
    ZoneId z = ZoneId.of( &quot;Europe/London&quot; ) ;
    ZonedDateTime zdt = ldt.atZone( z ) ;
&gt;zdt.toString() = 2023-06-22T23:38:03.466+01:00[Europe/London]
----------
Tip: Educate the publisher of your data about the benefits of using standard [ISO 8601][2] formats when communicating date-time values textually.
  [1]: https://ideone.com/UBK9uD
  [2]: https://en.wikipedia.org/wiki/ISO_8601
</details>
# 答案2
**得分**: 0
如果您有一个已知格式的字符串，您可以提取所需部分并构建任何接受这些部分的日期/时间对象，例如`ZonedDateTime`。
如果您需要一个`Date`对象，您可以基于`ZonedDateTime`来构建它。
```java
public static void main(String... args) {
    String str = "2023062223380346";
    ZonedDateTime zonedDateTime = convert(str, ZoneId.of("Europe/London"));
    System.out.println(zonedDateTime);  // 2023-06-22T23:38:03.000000046+01:00[Europe/London]
}
public static ZonedDateTime convert(String str, ZoneId zoneId) {
    return ZonedDateTime.of(Integer.parseInt(str.substring(0, 4)),
                            Integer.parseInt(str.substring(4, 6)),
                            Integer.parseInt(str.substring(6, 8)),
                            Integer.parseInt(str.substring(8, 10)),
                            Integer.parseInt(str.substring(10, 12)),
                            Integer.parseInt(str.substring(12, 14)),
                            Integer.parseInt(str.substring(14)),
                            zoneId);
}