Problemunvalidated
Mono.just(authentication.getPrincipal()) .ofType(UserDto.class) .filter(this::matchesExistingUser) // needs DTO .map(UserAuthenticationToken::from); // needs User, but. Outcome: So, there you would call your `userService.find(userDto)` and use this `Tuple2` downstream for those respective `filter` and `map` operators.
135420a5-3e52-478a-89ae-2b6e165bf08a
Mono.just(authentication.getPrincipal())
.ofType(UserDto.class)
.filter(this::matchesExistingUser) // needs DTO
.map(UserAuthenticationToken::from); // needs User, but. Outcome: So, there you would call your userService.find(userDto) and use this Tuple2 downstream for those respective filter and map operators.