[BUG] [JAVA] [SPRING] Map type request body incorrect in reactive spring

[ajithalbus]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Map types spec described with additionalProperties are generated incorrectly in spring reactive server code.
Example -

• OAI spec

...
requestBody:
  description: request
  content:
    application/json:
      schema:
        type: object
        additionalProperties:
          $ref: '#/components/schemas/DummyRequest'
...

• Generated code (for spring server with reactive="true")

... @Valid @RequestBody Mono<DummyRequest> requestBody, ...

• Expected code (for spring server with reactive="true")

... @Valid @RequestBody Mono<Map<String, DummyRequest>> requestBody, ...

openapi-generator version

v5.0.0-beta3

Generation Details

generatorName = "spring"
reactive = "true"

Suggest a fix

The template need to be updated.