[BUG] [sprind-cloud] Bean Validation for Type Optional is wrong

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

Invalid code for the type Optional with Bean Validation is generated.

openapi-generator version

5.0.1

OpenAPI declaration file content or url

If you post the code inline, please wrap it with

  /foo:
    post:
      operationId: createFoo
      responses:
        '200':
             content:
                text/plain:
                  schema:
                    type: string
                    format: binary
      parameters:
        - name: filename
          schema:
            type: string
            maxLength: 120
            pattern: '^[a-zA-Z0-9_-]*$'

Generation Details

Maven plugin

          <configuration>
                            <generatorName>spring</generatorName>
                            <configOptions>
                                <sortParamsByRequiredFlag>true</sortParamsByRequiredFlag>
                                <library>spring-cloud</library>
                                <java8>true</java8>
                                <dateLibrary>java8</dateLibrary>
                                <useOptional>true</useOptional>
                                <skipDefaultInterface>true</skipDefaultInterface>
                                <useBeanValidation>true</useBeanValidation>
                            </configOptions>

ResponseEntity<String> getFoo(
         @Pattern( regexp = "^[a-zA-Z0-9_-]*$" ) @Size( max = 120 )
         @ApiParam( value = "The filename of the Aspect Model input file." ) @Valid
         @RequestParam( value = "filename", required = false ) Optional<String> filename );

Steps to reproduce

Use bean validation with optionals

Suggest a fix

Generate valid code. The constraints have to be included in the Optional tag

ResponseEntity<String> getFoo(
       
         @ApiParam( value = "The filename of the Aspect Model input file." ) @Valid
         @RequestParam( value = "filename", required = false ) Optional< @Pattern( regexp = "^[a-zA-Z0-9_-]*$" ) @Size( max = 120 )String> filename );
`

Start by reproducing the issue with the Maven plugin using the spring generator, spring-cloud library, useOptional=true, and useBeanValidation=true, based on the inline OpenAPI parameter. Trace the generated Java method signature and the Bean Validation annotation templates; done means constraints for an optional parameter are placed inside Optional<> and the generated code is valid.