[Bug][Java] defaultValues for date and date-time params

[cachescrubber]

Support default values for Header and Cookie Params.

Fixes

• [BUG][JAVA] defaultValue not set for @RequestHeader in generated spring api file  #11392

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[cachescrubber]

@wing328 FYI. Who could help with the defaultValue date format issue?

[wing328]

Is toDefaultValue what you're looking for?

openapi-generator/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java

Line 896 in 9e1972b

public String toDefaultValue(Schema schema) {

I think you will need to override this method in the spring generator to address the issue above.

[cachescrubber]

Is stumbled up this line:

openapi-generator/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java

Line 984 in 9e1972b

return "OffsetDateTime.parse(\"" + String.format(Locale.ROOT, ((java.time.OffsetDateTime) schema.getDefault()).atZoneSameInstant(ZoneId.systemDefault()).toString(), "") + "\", java.time.format.DateTimeFormatter.ISO_ZONED_DATE_TIME.withZone(java.time.ZoneId.systemDefault()))";

What is the reasoning behind that?

[cachescrubber]

@wing328 The result of toDefaultValue is ignore for all parameter type other than queryParams. Why is that? Any hint?

[cachescrubber]

What is the reasoning behind that?

Answer to self: probably used to generate Model classes, not for Api method Parameter.

[cachescrubber]

Relates to #8577

[cachescrubber]

Slowly getting there. Need to find out why application/x-www-form-urlencoded are treated like model parameter.

[cachescrubber]

@wing328 I added some more tests to cover this issue. BTW, I think it might be okay to move

org.openapitools.codegen.languages.AbstractJavaCodegen#toDefaultParameterValue

to DefaultCodegen. WDYT?

[cachescrubber]

Surprisingly there are no samples affected by the last changes. Should I add date params with defaults to the more widely used examples?

[cachescrubber]

I did (local only). We would see stuff like the following (a groovy example)

    Date lastFeed = OffsetDateTime.parse("1973-12-19T11:39:57Z[UTC]", java.time.format.DateTimeFormatter.ISO_ZONED_DATE_TIME.withZone(java.time.ZoneId.systemDefault()))
    
    Date dateOfBirth = LocalDate.parse("2021-01-01")

so obviously the code in toDefaultValue() is not capable of supporting multiple Date libraries.

[cachescrubber]

Ich enhanced toDefaultValue to only return a default for date or date-time when dateTimeLibrary is java8. This way we can safely remove legacy date apis without introducing more bugs and broken samples in the meantime.

@wing328 I'm happy with the PR, please review.

[wing328]

cc @OpenAPITools/generator-core-team as the change covers default codegen: https://github.com/OpenAPITools/openapi-generator/pull/11536/files#diff-3a138675e8cb40943bcb00feb46edd6f6ee5c5306c29cc19f02c845a299c8658R6289