BeerServiceJPA.java

package guru.springframework.spring6restmvc.services;

import guru.springframework.spring6restmvc.mappers.BeerMapper;
import guru.springframework.spring6restmvc.model.BeerDTO;
import guru.springframework.spring6restmvc.repositories.BeerRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.context.annotation.Primary;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Optional;
import java.util.UUID;
import java.util.stream.Collectors;

/**
 * Created by jt, Spring Framework Guru.
 */
@Service
@Primary
@RequiredArgsConstructor
public class BeerServiceJPA implements BeerService {
    private final BeerRepository beerRepository;
    private final BeerMapper beerMapper;

    @Override
    public List<BeerDTO> listBeers() {
        return beerRepository.findAll()
                .stream()
                .map(beerMapper::beerToBeerDto)
                .collect(Collectors.toList());
    }

    @Override
    public Optional<BeerDTO> getBeerById(UUID id) {
        return Optional.ofNullable(beerMapper.beerToBeerDto(beerRepository.findById(id)
                .orElse(null)));
    }

    @Override
    public BeerDTO saveNewBeer(BeerDTO beer) {
        return beerMapper.beerToBeerDto(beerRepository.save(beerMapper.beerDtoToBeer(beer)));
    }

    @Override
    public Optional<BeerDTO> updateBeerById(UUID beerId, BeerDTO beer) {
        return beerRepository.findById(beerId)
                .map(foundBeer -> {
                    foundBeer.setBeerName(beer.getBeerName());
                    foundBeer.setBeerStyle(beer.getBeerStyle());
                    foundBeer.setUpc(beer.getUpc());
                    foundBeer.setPrice(beer.getPrice());
                    beerRepository.save(foundBeer);
                    return beerMapper.beerToBeerDto(foundBeer);
                });
    }

    @Override
    public Boolean deleteById(UUID beerId) {
        if (beerRepository.existsById(beerId)) {
            beerRepository.deleteById(beerId);
            return true;
        }
        return false;
    }

    @Override
    public void patchBeerById(UUID beerId, BeerDTO beer) {

    }
}