On Tue, 14 Jul 2026 18:42:10 GMT, Sholto <[email protected]> wrote:

>> Also covers: [8249280](https://bugs.openjdk.org/browse/JDK-8249280)
>> 
>> I will first give a quick summary of the problem.
>> Put simply, the `LocalDate` form of the `java.sql.Date` is derived using the 
>> `getYear` method of `java.util.Date`. This in turn returns the year of the 
>> normalised internal calendar.
>> However, the internal calendar `getYear` has an extra layer of complexity.
>> The calendar has an additional era field, which captures BC/AD.
>> `getYear` therefore just returns the year _of that era_.
>> For example, the year 6BC and the year 6AD both return `getYear` as 6.
>> 
>> **This means that for BC dates, our `LocalDate` conversion loses the sign of 
>> the year.**
>> 
>> This leads to additional problems down the line, as the year 1BC is for 
>> calculations sake is considered to be year 0 (and 2BC us considered year -1 
>> and so on). As a result, the various leap year calculations are WRONG for 
>> these years, causing year format validation failures in situations like 
>> marshalling/unmarshalling the dates with a DB.
>> 
>> There are two seemingly obvious fixes here, however I will attempt to 
>> explain why I did not proceed with them.
>> 
>> Firstly, it seems sensible is to derive the `LocalDate` from an `Instant` 
>> created from the millisecond representation of the `Date`. After all, why we 
>> are having to use the deprecated `getYear`, `getMonth` and `getDay` methods 
>> anyway?
>> The answer lies in [8061577](https://bugs.openjdk.org/browse/JDK-8061577).
>> The underlying millisecond representation between `java.time.Instant` and 
>> `java.util.Date` is fundamentally different. Read that ticket for a greater 
>> explanation.
>> Ultimately though, it means that the for older dates, the only real way to 
>> bridge between the two calendar systems is to use these year/month/day 
>> methods.
>> 
>> This is where the second possible solution appears.
>> The underlying calendar representation that `java.util.Date` uses actually 
>> does have a year method which gives you the correctly signed year, that 
>> being `getNormalizedYear`.
>> In fact, `java.util.Date` uses the setter counterpart `setNormalizedYear` is 
>> its `setYear` method.
>> Given this, it seems natural that `getYear` should similarly call 
>> `getNormalizedYear`.
>> I think this would be my ideal solution, however I recognise that `get`Year 
>> only returning a positive year is very long standing behaviour. Given how 
>> widely spread `java.util.Date` is, I felt it was perhaps better not to rock 
>> the boat too much.
>> 
>> I have therefore taken the decision to add an ...
>
> Sholto has updated the pull request incrementally with one additional commit 
> since the last revision:
> 
>   8272194: only use created calendar for BC check in LocalDate/LocalDateTime 
> conversion

Thanks for your changes so far. These are the only remaining issues I spotted.

src/java.sql/share/classes/java/sql/Timestamp.java line 567:

> 565:                                 getMinutes(),
> 566:                                 getSeconds(),
> 567:                                 getNanos()); // We have to use nanos 
> here as the calendar does not support nano precision

This comment is stale and can be removed.

test/jdk/java/sql/test/sql/DateTests.java line 334:

> 332:      * Ensures that the fix for 8272194 has not regressed.
> 333:      */
> 334:     @ParameterizedTest(autoCloseArguments = false)

I understand you are following the existing test convention, but I would remove 
the `autoCloseArguments = false` here and in the other occurrences since the 
parameter does not implement `AutoCloseable`, so it's just noise. (It is added 
to those other tests even though not needed as part of an earlier migration to 
conservatively match TestNG semantics.)

-------------

PR Review: https://git.openjdk.org/jdk/pull/31808#pullrequestreview-4698282197
PR Review Comment: https://git.openjdk.org/jdk/pull/31808#discussion_r3582413297
PR Review Comment: https://git.openjdk.org/jdk/pull/31808#discussion_r3582452309

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