[BUG] [Spring Boot] [Maven plugin] OpenAPI Generator 7.4.0 can't read OpenAPI 3.1 spec on Windows.

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

I tried upgrading an OpenAPI spec from 3.0.0 to 3.1.0, when I tried to generate the DTOs I need, the console is spammed with:

[ERROR] Error resolving schema #/components/schemas/SomeDTO
java.net.URISyntaxException: Illegal character in opaque part at index 2: C:\workspaces\.../src/main/resources/openapi.yaml
...
at io.swagger.v3.parser.reference.ReferenceUtils.resolve (ReferenceUtils.java:29)

This only appears to happen under Windows, while I can't reproduce this under WSL.

openapi-generator version

7.4.0

OpenAPI declaration file content or url

I don't have access to GitHub on the machine I can reproduce this on, though I'd assume this can be reproduced by any flat (single file) YAML OpenAPI document that uses $ref to refer to schemas or parameters.

Generation Details

This is a summary of relevant settings.

• generator: spring
• generateApiTests: false
• generateModelTests: false
• interfaceOnly: true
• useJakartaEe: true
• async: false

Steps to reproduce

Create OpenAPI spec of version 3.1
Add some model references using $ref: '#/components/schemas/MyDTO'
Attempt to generate (possibly with the maven plugin)

Related issues/PRs

None that I could find.

Suggest a fix

Start with the stack trace at ReferenceUtils.java:29 and reproduce the reported Spring generator or Maven plugin flow on Windows using an OpenAPI 3.1 YAML file with component $ref entries. Compare the Windows path handling with the WSL behavior; done means generation completes without the URISyntaxException for referenced schemas.