<i18n dev> RFR: 8299194: CustomTzIDCheckDST.java may fail at future date [v2]
Ichiroh Takiguchi
itakiguchi at openjdk.org
Wed Dec 21 23:21:42 UTC 2022
> test/jdk/java/util/TimeZone/CustomTzIDCheckDST.java may fail at future date.
> I used following standalone testcase
>
> import java.util.Calendar;
> import java.util.Date;
> import java.util.SimpleTimeZone;
>
> public class CheckDST {
> private static String CUSTOM_TZ = "MEZ-1MESZ,M3.5.0,M10.5.0";
> public static void main(String args[]) throws Throwable {
> runTZTest();
> }
>
> /* TZ code will always be set to "MEZ-1MESZ,M3.5.0,M10.5.0".
> * This ensures the transition periods for Daylights Savings should be at March's last
> * Sunday and October's last Sunday.
> */
> private static void runTZTest() {
> Date time = new Date();
> if (new SimpleTimeZone(3600000, "MEZ-1MESZ", Calendar.MARCH, -1, Calendar.SUNDAY, 0,
> Calendar.OCTOBER, -1, Calendar.SUNDAY, 0).inDaylightTime(time)) {
> // We are in Daylight savings period.
> if (time.toString().endsWith("GMT+02:00 " + Integer.toString(time.getYear() + 1900)))
> return;
> } else {
> if (time.toString().endsWith("GMT+01:00 " + Integer.toString(time.getYear() + 1900)))
> return;
> }
>
> // Reaching here means time zone did not match up as expected.
> throw new RuntimeException("Got unexpected timezone information: " + time);
> }
> }
>
>
> I tested CheckDST with faketime, then I got following results
>
> $ TZ=GMT faketime -m "2023-03-25 22:59:59" env TZ="MEZ-1MESZ,M3.5.0,M10.5.0" $HOME/jdk-21-b02/bin/java CheckDST
> $ TZ=GMT faketime -m "2023-03-25 23:00:00" env TZ="MEZ-1MESZ,M3.5.0,M10.5.0" $HOME/jdk-21-b02/bin/java CheckDST
> Exception in thread "main" java.lang.RuntimeException: Got unexpected timezone information: Sun Mar 26 00:00:00 GMT+01:00 2023
> at CheckDST.runTZTest(CheckDST.java:28)
> at CheckDST.main(CheckDST.java:8)
>
>
> I assume `TZ=MEZ-1MESZ`refers Europe/Berlin timezone.
> In this case, `TZ` environment variable should be `MEZ-1MESZ,M3.5.0,M10.5.0/3` (`/3` is missing in testcase)
>
> CustomTzIDCheckDST should run with daylight saving time.
> Add Simulate Southern Hemisphere by `MEZ-1MESZ,M10.5.0,M3.5.0/3`
>
> Tested by standalone testcase
>
> $ cat CheckDST1.java
> import java.util.Calendar;
> import java.util.Date;
> import java.util.List;
> import java.util.SimpleTimeZone;
> import java.util.TimeZone;
> import java.time.DayOfWeek;
> import java.time.ZonedDateTime;
> import java.time.temporal.TemporalAdjusters;
> public class CheckDST1 {
> // Northern Hemisphere
> private static String CUSTOM_TZ = "MEZ-1MESZ,M3.5.0,M10.5.0/3";
> // Simulate Southern Hemisphere
> private static String CUSTOM_TZ2 = "MEZ-1MESZ,M10.5.0,M3.5.0/3";
> public static void main(String args[]) throws Throwable {
> runTZTest();
> }
>
> /* TZ code will always be set to "MEZ-1MESZ,M3.5.0,M10.5.0/3".
> * This ensures the transition periods for Daylights Savings should be at March's last
> * Sunday and October's last Sunday.
> */
> private static void runTZTest() {
> Date time = new Date();
> String tzStr = System.getenv("TZ");
> if (tzStr == null)
> throw new RuntimeException("Got unexpected timezone information: TZ is null");
> boolean nor = tzStr.matches(".*,M3\..*,M10\..*");
> TimeZone tz = new SimpleTimeZone(3600000, tzStr,
> nor ? Calendar.MARCH : Calendar.OCTOBER, -1,
> Calendar.SUNDAY, 3600000, SimpleTimeZone.UTC_TIME,
> nor ? Calendar.OCTOBER : Calendar.MARCH, -1,
> Calendar.SUNDAY, 3600000, SimpleTimeZone.UTC_TIME,
> 3600000);
> System.out.println(time);
> if (tz.inDaylightTime(time)) {
> // We are in Daylight savings period.
> if (time.toString().endsWith("GMT+02:00 " + Integer.toString(time.getYear() + 1900)))
> return;
> } else {
> if (time.toString().endsWith("GMT+01:00 " + Integer.toString(time.getYear() + 1900)))
> return;
> }
>
> // Reaching here means time zone did not match up as expected.
> throw new RuntimeException("Got unexpected timezone information: " + tzStr + " " + time);
> }
>
> private static ZonedDateTime getLastSundayOfMonth(ZonedDateTime date) {
> return date.with(TemporalAdjusters.lastInMonth(DayOfWeek.SUNDAY));
> }
> }
>
>
> Check Europe/Berlin timezone settings
>
> $ zdump -v Europe/Berlin | grep 2023
> Europe/Berlin Sun Mar 26 00:59:59 2023 UTC = Sun Mar 26 01:59:59 2023 CET isdst=0 gmtoff=3600
> Europe/Berlin Sun Mar 26 01:00:00 2023 UTC = Sun Mar 26 03:00:00 2023 CEST isdst=1 gmtoff=7200
> Europe/Berlin Sun Oct 29 00:59:59 2023 UTC = Sun Oct 29 02:59:59 2023 CEST isdst=1 gmtoff=7200
> Europe/Berlin Sun Oct 29 01:00:00 2023 UTC = Sun Oct 29 02:00:00 2023 CET isdst=0 gmtoff=3600
>
>
> Test results are as follows:
>
> Northern Hemisphere side
>
> $ TZ=GMT faketime -m '2023-03-26 00:59:59' env TZ=MEZ-1MESZ,M3.5.0,M10.5.0/3 date
> Sun Mar 26 01:59:59 MEZ 2023
> $ TZ=GMT faketime -m '2023-03-26 00:59:59' env TZ=MEZ-1MESZ,M3.5.0,M10.5.0/3 java CheckDST1
> Sun Mar 26 01:59:59 GMT+01:00 2023
>
> $ TZ=GMT faketime -m '2023-03-26 01:00:00' env TZ=MEZ-1MESZ,M3.5.0,M10.5.0/3 date
> Sun Mar 26 03:00:00 MESZ 2023
> $ TZ=GMT faketime -m '2023-03-26 01:00:00' env TZ=MEZ-1MESZ,M3.5.0,M10.5.0/3 java CheckDST1
> Sun Mar 26 03:00:00 GMT+02:00 2023
>
> $ TZ=GMT faketime -m '2023-10-29 00:59:59' env TZ=MEZ-1MESZ,M3.5.0,M10.5.0/3 date
> Sun Oct 29 02:59:59 MESZ 2023
> $ TZ=GMT faketime -m '2023-10-29 00:59:59' env TZ=MEZ-1MESZ,M3.5.0,M10.5.0/3 java CheckDST1
> Sun Oct 29 02:59:59 GMT+02:00 2023
>
> $ TZ=GMT faketime -m '2023-10-29 01:00:00' env TZ=MEZ-1MESZ,M3.5.0,M10.5.0/3 date
> Sun Oct 29 02:00:00 MEZ 2023
> $ TZ=GMT faketime -m '2023-10-29 01:00:00' env TZ=MEZ-1MESZ,M3.5.0,M10.5.0/3 java CheckDST1
> Sun Oct 29 02:00:00 GMT+01:00 2023
>
>
> Southern Hemisphere side
>
> $ TZ=GMT faketime -m '2023-03-26 00:59:59' env TZ=MEZ-1MESZ,M10.5.0,M3.5.0/3 date
> Sun Mar 26 02:59:59 MESZ 2023
> $bTZ=GMT faketime -m '2023-03-26 00:59:59' env TZ=MEZ-1MESZ,M10.5.0,M3.5.0/3 java CheckDST1
> Sun Mar 26 02:59:59 GMT+02:00 2023
>
> $ TZ=GMT faketime -m '2023-03-26 01:00:00' env TZ=MEZ-1MESZ,M10.5.0,M3.5.0/3 date
> Sun Mar 26 02:00:00 MEZ 2023
> $ TZ=GMT faketime -m '2023-03-26 01:00:00' env TZ=MEZ-1MESZ,M10.5.0,M3.5.0/3 java CheckDST1
> Sun Mar 26 02:00:00 GMT+01:00 2023
>
> $ TZ=GMT faketime -m '2023-10-29 00:59:59' env TZ=MEZ-1MESZ,M10.5.0,M3.5.0/3 date
> Sun Oct 29 01:59:59 MEZ 2023
> $ TZ=GMT faketime -m '2023-10-29 00:59:59' env TZ=MEZ-1MESZ,M10.5.0,M3.5.0/3 java CheckDST1
> Sun Oct 29 01:59:59 GMT+01:00 2023
>
> $ TZ=GMT faketime -m '2023-10-29 01:00:00' env TZ=MEZ-1MESZ,M10.5.0,M3.5.0/3 date
> Sun Oct 29 03:00:00 MESZ 2023
> $ TZ=GMT faketime -m '2023-10-29 01:00:00' env TZ=MEZ-1MESZ,M10.5.0,M3.5.0/3 java CheckDST1
> Sun Oct 29 03:00:00 GMT+02:00 2023
Ichiroh Takiguchi has updated the pull request incrementally with one additional commit since the last revision:
8299194: CustomTzIDCheckDST.java may fail at future date
-------------
Changes:
- all: https://git.openjdk.org/jdk/pull/11756/files
- new: https://git.openjdk.org/jdk/pull/11756/files/a17d83d0..df2e8a86
Webrevs:
- full: https://webrevs.openjdk.org/?repo=jdk&pr=11756&range=01
- incr: https://webrevs.openjdk.org/?repo=jdk&pr=11756&range=00-01
Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
Patch: https://git.openjdk.org/jdk/pull/11756.diff
Fetch: git fetch https://git.openjdk.org/jdk pull/11756/head:pull/11756
PR: https://git.openjdk.org/jdk/pull/11756
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