<i18n dev> RFR: JDK-8318761: MessageFormat pattern support for CompactNumberFormat, ListFormat, and DateTimeFormatter [v2]

[Naoto Sato]

On Fri, 2 Feb 2024 22:16:30 GMT, Justin Lu <jlu at openjdk.org> wrote:

>> Please review this PR and [CSR](https://bugs.openjdk.org/browse/JDK-8319344) which adds MessageFormat pattern support for the following subformats: ListFormat, CompactNumberFormat, and DateTimeFormatter. This change is intended to provide pattern support for the more recently added JDK Format subclasses, as well as improving java.time formatting within i18n. The draft javadoc can be viewed here: https://cr.openjdk.org/~jlu/docs/api/java.base/java/text/MessageFormat.html. Please see the CSR for more in-depth behavioral changes, as well as limitations.
>> 
>> The `FormatTypes`:  dtf_date, dtf_time, dtf_datetime, pre-defined DateTimeFormatter(s), and list are added.
>> The `FormatStyles`: compact_short, compact_long, or, and unit are added.
>> 
>> For example, previously,
>> 
>> 
>> Object[] args = {LocalDate.of(2023, 11, 16), LocalDate.of(2023, 11, 27)};
>> MessageFormat.format("It was {0,date,full}, now it is {1,date,full}", args);
>> 
>> 
>> would throw `Exception java.lang.IllegalArgumentException: Cannot format given Object as a Date`
>> 
>> Now, a user can call
>> 
>> 
>> MessageFormat.format("It was {0,dtf_date,full}, now it is {1,dtf_date,full}", args);
>> 
>> 
>> which returns "It was Thursday, November 16, 2023, now it is Friday, November 17, 2023"
>
> Justin Lu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   reflect Naoto's comments

src/java.base/share/classes/java/text/MessageFormat.java line 377:

> 375:  * Calendar cal = Calendar.getInstance();
> 376:  * cal.set(123 + 1900, 10, 16);
> 377:  * Object[] arg = {cal.getTime()};

Maybe with the following, better aligned with `java.time`'s example?

Object[] arg = {new GregorianCalendar(2023, Calendar.NOVEMBER, 16).getTime()};

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PR Review Comment: https://git.openjdk.org/jdk/pull/17663#discussion_r1476820208