RFR: JDK-8079063 ZoneOffsetTransition constructor should ignore nanoseconds

Stephen Colebourne scolebourne at joda.org
Wed May 6 15:06:04 UTC 2015


I am also happy with this change.

Stephen


On 6 May 2015 at 15:43, Roger Riggs <Roger.Riggs at oracle.com> wrote:
> Hi Peter,
>
> Thanks for the analysis and followup.
>
> Yes, I think thesimple check as you propose is the desired clarification.
> I agree that the change should not affect any existing code outside the JDK
> and does not raise a compatibility issue.
>
> Roger
>
>
>
> On 5/4/2015 6:22 AM, Peter Levart wrote:
>>
>> Hi,
>>
>> Now that JDK-8074003 is in, I'd like to discuss how to tackle JDK-8079063.
>>
>> Package-private ZoneOffsetTransition constructor that takes LocalDateTime
>> transition is invoked from the following 4 places:
>>
>> 1 - the public static factory method:
>>
>>     /**
>>      * Obtains an instance defining a transition between two offsets.
>>      * <p>
>>      * Applications should normally obtain an instance from {@link
>> ZoneRules}.
>>      * This factory is only intended for use when creating {@link
>> ZoneRules}.
>>      *
>>      * @param transition  the transition date-time at the transition,
>> which never
>>      *  actually occurs, expressed local to the before offset, not null
>>      * @param offsetBefore  the offset before the transition, not null
>>      * @param offsetAfter  the offset at and after the transition, not
>> null
>>      * @return the transition, not null
>>      * @throws IllegalArgumentException if {@code offsetBefore} and {@code
>> offsetAfter}
>>      *         are equal, or {@code transition.getNano()} returns non-zero
>> value
>>      */
>>     public static ZoneOffsetTransition of(LocalDateTime transition,
>> ZoneOffset offsetBefore, ZoneOffset offsetAfter) {
>>
>> ...this one already disallows transition parameters that have
>> transition.getNano() != 0.
>>
>>
>> 2 - Lines 498..500 of ZoneOffsetTransitionRule:
>>
>>         LocalDateTime localDT = LocalDateTime.of(date, time);
>>         LocalDateTime transition = timeDefinition.createDateTime(localDT,
>> standardOffset, offsetBefore);
>>         return new ZoneOffsetTransition(transition, offsetBefore,
>> offsetAfter);
>>
>> ...where 'time' is an instance field of ZoneOffsetTransitionRule. The
>> ZoneOffsetTransitionRule public static factory method has the following
>> definition:
>>
>>     /**
>>      * Obtains an instance defining the yearly rule to create transitions
>> between two offsets.
>>      * <p>
>>      * Applications should normally obtain an instance from {@link
>> ZoneRules}.
>>      * This factory is only intended for use when creating {@link
>> ZoneRules}.
>>      *
>>      * @param month  the month of the month-day of the first day of the
>> cutover week, not null
>>      * @param dayOfMonthIndicator  the day of the month-day of the cutover
>> week, positive if the week is that
>>      *  day or later, negative if the week is that day or earlier,
>> counting from the last day of the month,
>>      *  from -28 to 31 excluding 0
>>      * @param dayOfWeek  the required day-of-week, null if the month-day
>> should not be changed
>>      * @param time  the cutover time in the 'before' offset, not null
>>      * @param timeEndOfDay  whether the time is midnight at the end of day
>>      * @param timeDefnition  how to interpret the cutover
>>      * @param standardOffset  the standard offset in force at the cutover,
>> not null
>>      * @param offsetBefore  the offset before the cutover, not null
>>      * @param offsetAfter  the offset after the cutover, not null
>>      * @return the rule, not null
>>      * @throws IllegalArgumentException if the day of month indicator is
>> invalid
>>      * @throws IllegalArgumentException if the end of day flag is true
>> when the time is not midnight
>>      */
>>     public static ZoneOffsetTransitionRule of(
>>             Month month,
>>             int dayOfMonthIndicator,
>>             DayOfWeek dayOfWeek,
>>             LocalTime time,
>>             boolean timeEndOfDay,
>>             TimeDefinition timeDefnition,
>>             ZoneOffset standardOffset,
>>             ZoneOffset offsetBefore,
>>             ZoneOffset offsetAfter) {
>>         Objects.requireNonNull(month, "month");
>>         Objects.requireNonNull(time, "time");
>>         Objects.requireNonNull(timeDefnition, "timeDefnition");
>>         Objects.requireNonNull(standardOffset, "standardOffset");
>>         Objects.requireNonNull(offsetBefore, "offsetBefore");
>>         Objects.requireNonNull(offsetAfter, "offsetAfter");
>>         if (dayOfMonthIndicator < -28 || dayOfMonthIndicator > 31 ||
>> dayOfMonthIndicator == 0) {
>>             throw new IllegalArgumentException("Day of month indicator
>> must be between -28 and 31 inclusive excluding zero");
>>         }
>>         if (timeEndOfDay && time.equals(LocalTime.MIDNIGHT) == false) {
>>             throw new IllegalArgumentException("Time must be midnight when
>> end of day flag is true");
>>         }
>>         return new ZoneOffsetTransitionRule(month, dayOfMonthIndicator,
>> dayOfWeek, time, timeEndOfDay, timeDefnition, standardOffset, offsetBefore,
>> offsetAfter);
>>     }
>>
>> ...which allows 'time' parameter (that becomes ZoneOffsetTransitionRule's
>> 'time' field) with no restriction as to whether it can contain nanos != 0 or
>> not.
>>
>>
>> 3, 4 - Lines 668..678 of ZoneRules private getOffsetInfo method:
>>
>>             LocalDateTime dtBefore = savingsLocalTransitions[index];
>>             LocalDateTime dtAfter = savingsLocalTransitions[index + 1];
>>             ZoneOffset offsetBefore = wallOffsets[index / 2];
>>             ZoneOffset offsetAfter = wallOffsets[index / 2 + 1];
>>             if (offsetAfter.getTotalSeconds() >
>> offsetBefore.getTotalSeconds()) {
>>                 // gap
>>                 return new ZoneOffsetTransition(dtBefore, offsetBefore,
>> offsetAfter);
>>             } else {
>>                 // overlap
>>                 return new ZoneOffsetTransition(dtAfter, offsetBefore,
>> offsetAfter);
>>             }
>>
>> ...where dtBefore/dtAfter "transition" parameters are taken from
>> savingsLocalTransitions[] array that is filled-in in ZoneRules constructors
>> from passed-in ZoneOffsetTransition objects. So here no nanos != 0 can sneak
>> in if ZoneOffsetTransition invariant holds.
>>
>> The only place where nanos can sneak-in therefore seems to be the public
>> ZoneOffsetTransitionRule.of() factory method. The question is whether the
>> spec. could be changed so that ZoneOffsetTransitionRule.of() factory method
>> would add another @throws definition:
>>
>>      * @throws IllegalArgumentException if {@code time.getNano()} returns
>> non-zero value
>>
>>
>> This, I think, would be consistent with ZoneOffsetTransition.of() factory
>> method and I believe early enough in the live of the API so that no custom
>> software would be affected:
>>
>>
>> http://cr.openjdk.java.net/~plevart/jdk9-dev/ZoneOffsetTransitionRule.time/webrev.01/
>>
>> What do you think?
>>
>> Regards, Peter
>>
>



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