Spring Boot App with OAuth2.0 User Roles

I need a Spring Boot application with OAuth2.0 protocol that manages both Admin and User roles. The core of this application is its user management feature, which involves role assignment and modification.

Key Requirements:
- User Authentication: The application should authenticate a user once they have successfully logged in.
- Role Management: After logging in, the application should check whether the user is an admin or a regular user.
- User Management Features: The application should include user management capabilities, specifically the ability to assign and modify roles for different users.

Ideal Skills and Experience:
- Proficiency in Spring Boot framework
- In-depth knowledge of OAuth2.0 protocol
- Experience in developing user management systems
- Ability to implement role assignment and modification features
- Strong understanding of user authentication processes