PropertiesStoreTest and StoreReproducibilityTest jtreg failures due to en_CA locale

Both PropertiesStoreTest and StoreReproducibilityTest jtreg tests fail when run on a system whose default locale is en_CA (likely anything other than US)

Issue:

The Properties class serializes via the store method and adds a Date comment using Date.toString(), this results in a date looking like: Wed Feb 16 09:27:53 PST 2022

The tests in question use DateTimeFormatter.ofPattern(pattern).parse(text) to read and verify the comment

where the pattern is: "EEE MMM dd HH:mm:ss zzz uuuu"

This will parse successfully on US systems, however DateTimeFormatter uses the default locale which for en_CA expects the strings for EEE and MMM to end in a period/full-stop e.g.

Wed. Feb. 16 09:27:53 PST 2022

Root cause:

Date.toString() always outputs in "US" styled format (it doesn't use any localization)

DateFormatter.ofPattern(pattern).parse(text) defaults to the current locale

Solution:

Change the tests to use US locale: DateTimeFormatter.ofPattern(pattern, Locale.US).parse(text)

Recommendations:

Add a further test to check for regressions in either of Date or DateTimeFormatter by testing:

DateTimeFormatter.ofPattern("EEE MMM dd HH:mm:ss zzz uuuu", Locale.US).parse(new Date().toString())