Rewriting a method to use Optional without changing anything outside this method

I have came across this code.

public AnimalResponse getAnimal(Specie specie) {
    AnimalEntity animal = speciesRepository.findBySpecie(specie).orElseThrow(
        () - > new ResourceNotFoundException(specie)
    ).getAnimal();

    if (animal == null) {
        throw new NoAnimalException();
    }

    return getAnimal(animal.getId());
}

getAnimal() method may return null, so later on invoking getId() on that object leads to NPE. Hence null check is used that I want to avoid.

I was wondering: how can I re-write this method for it to use Optionals and maintain the same functionality? Is it doable, will it be cleaner?

I realize this method is confusing at best, but I don't want to change anything outside this method, and struggle to make anything out of Optional work.

trdanv's answer is about as good as it gets without changing the behaviour.

If you are able to consolidate the two exceptions into one which covers either Animal being null or species not being found, then you are able to use Optional much more idiomatically

return speciesRepository.findBySpecie(specie)
    .map(Species::getAnimal)
    .map(AnimalEntity::getId)
    .map(this::getAnimal)
    .orElseThrow(() -> new AnotherException(specie));

Basically my ideal is we map species to animal before we throw exception

AnimalEntity animal = speciesRepository.findBySpecie(specie)
        .map(spec -> spec.getAnimal())
        .orElseThrow(() -> new ResourceNotFoundException(specie));
return getAnimal(animal.getId());

If I understand correctly, you can wrap it in a Optional.ofNullable() like so:

public AnimalResponse getAnimal(Specie specie) {
    AnimalEntity animal = Optional.ofNullable(speciesRepository
            .findBySpecie(specie)
            .orElseThrow(() - >
                new ResourceNotFoundException(specie))
            .getAnimal())
        .orElseThrow(() - > new NoAnimalException());

    return getAnimal(animal.getId());
}