Java Desktop App API Authentication

I need a Java desktop application integrated with basic authentication for a REST API. Additionally, I require user role management as part of the authentication process and i clear i dont have project file i have only .jar file.

Requirements:
- Implement Basic Authentication for REST API
- Integrate user role management features

Ideal Skills and Experience:
- Proficient in Java
- Experience with API authentication
- Familiarity with user role management systems
- Prior work on desktop applications

Please provide examples of similar work done.