[Spring JPA](2) 회원 & 상품 도메인 개발

(1) 회원 도메인 개발

 

구현 기능
1. 회원 등록
2. 회원 목록 조회

 

MemberRepository

package jpabook.jpashop.repository;

import jakarta.persistence.EntityManager;
import jpabook.jpashop.domain.Member;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
@RequiredArgsConstructor
public class MemberRepositoryOld {
    private final EntityManager em;

    public void save(Member member) {
        em.persist(member);
    }

    public Member findOne(Long id) {
        return em.find(Member.class, id);
    }

    public List<Member> findAll() {
        return em.createQuery("select m from Member m", Member.class)
                .getResultList();
    }

    public List<Member> findByName(String name) {
        return em.createQuery("select m from Member m where m.name = :name", Member.class)
                .setParameter("name", name)
                .getResultList();
    }
}

 

MemberService

package jpabook.jpashop.service;

import jpabook.jpashop.domain.Member;
import jpabook.jpashop.repository.MemberRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
@Transactional(readOnly = true)
@RequiredArgsConstructor
public class MemberService {
    private final MemberRepository memberRepository;

    /**
     * 회원 가입
     */
    @Transactional
    public Long join(Member member) {
        validateDuplicateMember(member);
        memberRepository.save(member);
        return member.getId();
    }

    private void validateDuplicateMember(Member member) {
        List<Member> findMembers = memberRepository.findByName(member.getName());
        if (!findMembers.isEmpty()) {
            throw new IllegalStateException("이미 존재하는 회원입니다.");
        }
    }

    /**
     * 회원 전체 조회
     */
    public List<Member> findMembers() {
        return memberRepository.findAll();
    }

    public Member findOne(Long memberId) {
        return memberRepository.findById(memberId).get();
    }

    @Transactional
    public void update(Long id, String name) {
        Member member = memberRepository.findById(id).get();
        member.setName(name);
    }
}

실무에서는 검증 로직이 있어도 멀티 쓰레드 상황을 고려하여 회원 테이블의 회원명 컬럼에 유니크 제약 조건을 추가하는 것이 안전하다.

 

MemberServiceTest

package jpabook.jpashop.service;

import jpabook.jpashop.domain.Member;
import jpabook.jpashop.repository.MemberRepository;
import org.junit.jupiter.api.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.transaction.annotation.Transactional;

import static org.junit.Assert.*;

@RunWith(SpringRunner.class)
@SpringBootTest
@Transactional
class MemberServiceTest {
    @Autowired
    MemberService memberService;
    @Autowired
    MemberRepository memberRepository;

    @Test
    public void 회원가입() throws Exception {
        Member member = new Member();
        member.setName("kim");

        Long savedId = memberService.join(member);

        assertEquals(member, memberRepository.findById(savedId).get());
    }

    @Test
    public void 중복_회원_예외() throws Exception {
        Member member1 = new Member();
        member1.setName("kim");

        Member member2 = new Member();
        member2.setName("kim");

        memberService.join(member1);

        assertThrows(IllegalStateException.class, () -> {
            memberService.join(member2);
        });
    }
}

 

테이스 케이스를 위한 설정

테스트는 케이스 격리된 환경에서 실행하고, 끝나면 데이터를 초기화하는 것이 좋다. 그런 면에서 메모리 DB를 사용하는 것이 가장 이상적이다.

*test/resources/application.yml

spring:
#  datasource:
#    url: jdbc:h2:mem:testdb
#    username: sa
#    password:
#    driver-class-name: org.h2.Driver
#  jpa:
#    hibernate:
#      ddl-auto: create
#    properties:
#      hibernate:
#        #show_sql: true
#        format_sql: true

logging.level:
  org.hibernate.SQL: debug

 

 

(2) 상품 도메인 개발

 

구현 기능
1. 상품 등록
2. 상품 목록 조회 

3. 상품 수정

 

Item

상품 엔티티에 비즈니스 로직 추가

package jpabook.jpashop.domain.item;

import jakarta.persistence.*;
import jpabook.jpashop.domain.Category;
import jpabook.jpashop.exception.NotEnoughStockException;
import lombok.Getter;
import lombok.Setter;

import java.util.ArrayList;
import java.util.List;

@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "dtype")
@Getter
@Setter
public abstract class Item {
    @Id
    @GeneratedValue
    @Column(name = "item_id")
    private Long id;

    private String name;
    private int price;
    private int stockQuantity;

    @ManyToMany(mappedBy = "items")
    private List<Category> categories = new ArrayList<>();

    //==비즈니스 로직==//

    /**
     * stock 증가
     */
    public void addStock(int quantity) {
        this.stockQuantity += quantity;
    }

    /**
     * stock 감소
     */
    public void removeStock(int quantity) {
        int restStock = this.stockQuantity - quantity;
        if (restStock < 0) {
            throw new NotEnoughStockException("need more stock");
        }
        this.stockQuantity = restStock;
    }
}

 

예외 추가

package jpabook.jpashop.exception;

public class NotEnoughStockException extends RuntimeException {
    public NotEnoughStockException() {
        super();
    }

    public NotEnoughStockException(String message) {
        super(message);
    }

    public NotEnoughStockException(String message, Throwable cause) {
        super(message, cause);
    }

    public NotEnoughStockException(Throwable cause) {
        super(cause);
    }
}

 

ItemRespository

package jpabook.jpashop.repository;

import jakarta.persistence.EntityManager;
import jpabook.jpashop.domain.item.Item;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
@RequiredArgsConstructor
public class ItemRepository {
    private final EntityManager em;

    public void save(Item item) {
        if (item.getId() == null) {
            em.persist(item);
        } else {
            em.merge(item);
        }
    }

    public Item findOne(Long id) {
        return em.find(Item.class, id);
    }

    public List<Item> findAll() {
        return em.createQuery("select i from Item i", Item.class)
                .getResultList();
    }
}

 

ItemService

package jpabook.jpashop.service;

import jpabook.jpashop.domain.item.Item;
import jpabook.jpashop.repository.ItemRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
@Transactional(readOnly = true)
@RequiredArgsConstructor
public class ItemService {
    private final ItemRepository itemRepository;

    @Transactional
    public void saveItem(Item item) {
        itemRepository.save(item);
    }

    public List<Item> findItems() {
        return itemRepository.findAll();
    }

    public Item findOne(Long itemId) {
        return itemRepository.findOne(itemId);
    }
    
    /**
     * 영속성 컨텍스트가 자동 변경
     */
    @Transactional
    public void updateItem(Long id, String name, int price, int stockQuantity) {
        Item item = itemRepository.findOne(id);
        item.setName(name);
        item.setPrice(price);
        item.setStockQuantity(stockQuantity);
    }
}