Non-spring java sdk and example to put in filters for authentication validation?

Is there an example of just POJO logic without spring on validating a token from auth0? We have react on the client side and java on the server side. This library has a ton of client side methods GitHub - auth0/auth0-java: Java client library for the Auth0 platform and I am wondering if there is a library server side for simple validation and where I get the keys and such to hash/compare…

Back to my original question, is there a server side authentication (and I probably can figure out authorization once I get the roles from the JWT token and know the token is valid).
thanks,
dean