[Aias00]

Purpose of the pull request

Closed: #1157

Default date conversion silently normalized invalid calendar strings instead of reporting malformed input.

What's changed?

• Disable lenient parsing for cached SimpleDateFormat instances.
• Build java.time formatters with strict resolver semantics, normalizing unquoted y to u for patterns without an explicit era so yyyy remains valid without conflicting with proleptic years.
• Add DateUtils and converter tests for invalid month-end/leap-day values, valid controls, negative and zero years, quoted literals, and explicit eras.

Verification:

JDK 21: DateUtilsTest, DateStringConverterTest, LocalDateStringConverterTest,
OffsetDateTimeConverterTest, YearStringConverterTest, CharacterAndYearFieldRoundTripTest
Tests run: 127, Failures: 0, Errors: 0, Skipped: 0
spotless:check: passed

Checklist

• I have read the Contributor Guide.
• I have written the necessary doc or comment.
• I have added the necessary unit tests and all cases have passed.

[bengbengbalabalabeng]

Thanks for the contribution. Please resolve the merge conflicts and update the PR when you have a chance.

[bengbengbalabalabeng]

Thanks for the contribution. Please resolve the merge conflicts and update the PR when you have a chance.

@Aias00 :)

[Aias00]

Thanks for the contribution. Please resolve the merge conflicts and update the PR when you have a chance.

done 😊