[BUG][Java] Bean Validation Breaks Generated Java Code

Created by: AdrianDiemerDev

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

When using the "useBeanValidation" option with an openAPI specification that has a required request body, the Java generator for okhttp-gson (and I think others, too) generates invalid Java code due to a missing white space.

openapi-generator version

This happens only from version 5.3.0 onwards.

OpenAPI declaration file content or url

openapi: "3.0.3"
info:
  title: Bla API
  version: "1.0.2"
  description: RESTful Bla API.
  license:
    name: "bla"
    url: "http://bla.com"
servers:
  - url: https://localhost:8080/bla
paths:
  /configuration:
    put:
      operationId: operation
      description: bla
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              minProperties: 1
              additionalProperties:
                type: object
      responses:
        '200':
          description: OK

This generates the line

public ApiResponse<Void> operationWithHttpInfo( @NotNullMap<String, Object> requestBody) throws ApiException

when it should be

public ApiResponse<Void> operationWithHttpInfo( @NotNull Map<String, Object> requestBody) throws ApiException

Generation Details

Options:

useBeanValidation: true  

docker run --rm -v "${PWD}:/local" openapitools/openapi-generator-cli generate -i /local/openapi.yaml -g java -c /local/options.yaml -o /local/out

Steps to reproduce

Related issues/PRs

Suggest a fix

I think the issue might have been introduced here and could probably be resolved be reintroducing the whitespace (maybe even directly after "NotNull"). However, I have no experience with these templates and no idea which other places might need to be checked.