[BUG][java-vertx-web] Textual responses get wrapped in JSON

Description

Textual responses get wrapped in JSON, the current template calls .json regardless of output type.

if (apiResponse.hasData()) {
    routingContext.json(apiResponse.getData());
}

openapi-generator version

7.2.0
Also checked on latest master via Docker

OpenAPI declaration file content or url

openapi: 3.0.3
info:
  title: Example
  version: 1.0.0
paths:
  /example:
    post:
      operationId: postExample
      responses:
        200:
          description: Successful operation
          content:
            text/plain:
              schema:
                type: string

Generation Details

openapi-generator generate \
  -i ./api.yaml \
  "-g" "java-vertx-web"

Steps to reproduce

Run the above command

Related issues/PRs

Suggest a fix

Not the cleanest, but apiHandler.mustache can be:

...
                    var data = apiResponse.getData();
                    if ((Object) data instanceof String s) {
                        routingContext.response().end(s);
                    } else {
                        routingContext.json(data);
                    }
...

Start with the java-vertx-web template's apiHandler.mustache and reproduce the issue using the supplied OpenAPI YAML and generation command. Verify that a text/plain string response is sent as text rather than wrapped in JSON, while the existing JSON response behavior remains unchanged.