[BUG][SPRING] Default value for query parameter not exported to code and doc

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

openapi: 3.0.0
Default value for query parameter not exported to code and doc.

openapi-generator version

Current, available in https://app.swaggerhub.com

OpenAPI declaration file content or url

https://app.swaggerhub.com/apis/marikori/default_value_bug/1.0.0

Command line used for generation

Use swaggerhub UI to generate documentation - Export -> Documentation -> html2:

Use swaggerhub UI to generate code - Export -> Server Stub -> spring:

Steps to reproduce

1. Define default value for parameter in OAS - line 14 (dafault = 0 for par1) in https://app.swaggerhub.com/apis/marikori/default_value_bug/1.0.0
2. Export html2 documentation using codegen available in swaggerbub (see above).
3. Export Spring server code using codegen available in swaggerbub (see above).

Results:
2. Default value not defined in exported documentation.
3. Default value not define in exported code.

exported_code_and_doc.tar.gz

Related issues/PRs

Suggest a fix

Start by reproducing the issue with the OpenAPI declaration at SwaggerHub, using the documented Export > Documentation > html2 and Export > Server Stub > spring entry points. Compare the generated documentation and Spring server code for the parameter on line 14, and consider the issue done when its default value appears correctly in both outputs.