How can reactive programming be enabled for key-cache?

[MarcGiffing]

Discussed in #286

^{Originally posted by dwang2 April 7, 2024}
I have developed a reactive security service to retrieve the current user's name using the code snippet provided below. How can I formulate a key-cache expression to asynchronously fetch the username

@service
public class SecurityService {

public Mono<String> username() {
	return ReactiveSecurityContextHolder.getContext()
			.map(securityContext -> {
				Authentication authentication = securityContext.getAuthentication();
				return authentication != null ? authentication.getName() : null;
			});
}

}

[dwang2]

Given that we are using Spring version 2.7.x, could you please extend support to version 0.8.x as well? This aligns with the current version I'm using.