jpa 엔티티 매핑

さようなら。冬·2020년 12월 31일
0

Locker <---> Member 1:1 양방향

Member <----> Team N:1 양방향

@Entity
@Getter
@Setter
public class Locker {

	@Id
	@GeneratedValue
	@Column(name="locker_id")
	private long id;
	private String name;
	
	@OneToOne(mappedBy="locker")
	private Member member;
	
	public Locker(String name) {
		this.name= name;
	}

	public void setMember(Member member) 
	{
		if(member.getLocker()!=this)
			member.setLocker(this);
	    	
	}
	
	
}
 
@Entity
@NoArgsConstructor
@Getter
@Setter

public class Member {
	@Id
	@GeneratedValue

	private long id;
	private String name;

	@ManyToOne
	@JoinColumn(name="TEAM_ID")
	private Team team;
	
	
	@OneToOne
	@JoinColumn(name="locker_id")
	private Locker locker;
	
	//무한 루프를 막는 로직
	public void setTeam(Team team) 
	{
		//양방향이라 맵핑 되는 부분을 서로 셋팅을 해줘야 하는데 .
		//일단 Member 의 team은 셋팅
		 this.team = team;
		 //Team에도 Member를 셋팅하기 전에 이미 member가 포함되어있지 않아야만 셋팅 해줄수있다 Team클래스도 마찬가지 
		 if(!team.getMembers().contains(this)) 
		 {
			 team.getMembers().add(this);
		 }
	}
	
	public void setLocker(Locker locker) 
	{
		this.locker= locker;
		if(locker.getMember() == null) 
		{
			locker.setMember(this);
		}
	}

	public Member(String name) {
		this.name= name;
	}
}

실행 로직


@Component
@Transactional 
public class JpaRunner implements ApplicationRunner{
	@PersistenceContext
	EntityManager entityManager;
 	public void oneToOne() 
	{
 
		Member member1 = new Member("member1");
		Member member2 = new Member("member2");
		Member member3 = new Member("member3");
		entityManager.persist(member1);
		entityManager.persist(member2);
		entityManager.persist(member3);
		
		
		Locker locker1 = new Locker("locker4");
		Locker locker2 = new Locker("locker5");
		Locker locker3 = new Locker("locker6");
		entityManager.persist(locker1);
		entityManager.persist(locker2);
		entityManager.persist(locker3);

		member1.setLocker(locker1);
		member2.setLocker(locker2);
		member3.setLocker(locker3);
	}
	
	public void ManyToOne() 
	{
		
	}

	@Override
	public void run(ApplicationArguments args) throws Exception {
		oneToOne();
	}

 
	
	
}

참고 : 김영한님의 jpa 교재

0개의 댓글