[Java] 순수한 Java 코드로 JPA 익혀보기

순수한 Java 코드만 이용하여 JPA 익히기

클래스 아래쪽으로 Entity, Repository, Service, Controller 전부 생성

제일 큰 test class 안쪽으로 Beverage로 돌려보기

public class BeverageController {
        private final BeverageService beverageService;

        public void deleteDrink(String name) {
            Beverage beverage = beverageService.deletebeverage(name);
        }
    }

Controller 단에 name을 기준으로 delete 하는 메서드 생성
그러면 Service단에 deletebeverage라는 메서드가 있어야 함

    public class BeverageService {
        private final BeverageRepository beverageRepository;

        public BeverageService(BeverageRepository beverageRepository) {
            this.beverageRepository = beverageRepository;
        }

        public Beverage createDrink(String name, Long price, Date date, Long ea) {
            Beverage beverage = new Beverage(name, price, date, ea);
            beverage.setName(name);
            beverage.setPrice(price);
            beverage.setEa(ea);
            beverage.setDate(date);
            return beverageRepository.save(beverage);
        }

        public Beverage getBeverage(String name) {
            return beverageRepository.findDrinkByName(name)
                    .orElseThrow(() -> new RuntimeException("해당 제품 없음"));
        }

        public Beverage deletebeverage(String name) {
            Beverage beverage = getBeverage(name);
            beverageRepository.delete(beverage);
            return beverage;
        }
    }

이번엔 Repository단에 delete라는 메서드가 있어야 함

public class BeverageRepository {
        public final Map<String, Beverage> assistance = new HashMap<>();
        public final Map<Long, Beverage> assistance2 = new HashMap<>();
        public final Map<Date, Beverage> assistance3 = new HashMap<>();

        public List<Beverage> getAllDrinkByName() {
            return new ArrayList<>(assistance2.values());
        }

        public Beverage save(Beverage beverage) {
            assistance2.put(beverage.getId(), beverage);
            return beverage;
        }

        public void delete(Beverage beverage) {
            assistance.remove(beverage.getName());
        }
    }