[JPA-Error] org.hibernate.TransientObjectException: object references an unsaved transient instance

Embedded 값 타입을 다루고 있는데 오류가 발생했다.

javax.persistence.RollbackException: Error while committing the transaction
	at org.hibernate.internal.ExceptionConverterImpl.convertCommitException(ExceptionConverterImpl.java:81)
	at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:104)
	at jpay.jpastudy.JpastudyApplication.main(JpastudyApplication.java:44)
Caused by: java.lang.IllegalStateException: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: jpay.jpastudy.PhoneServiceProvider
	at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:151)
	at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:181)
	at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:188)
	at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1411)
	at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:489)
	at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3303)
	at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2438)
	at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:449)
	at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:183)
	at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$300(JdbcResourceLocalTransactionCoordinatorImpl.java:40)
	at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:281)
	at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:101)
	... 1 more
Caused by: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: jpay.jpastudy.PhoneServiceProvider
	at org.hibernate.engine.internal.ForeignKeys.getEntityIdentifierIfNotUnsaved(ForeignKeys.java:347)
	at org.hibernate.type.EntityType.getIdentifier(EntityType.java:508)
	at org.hibernate.type.ManyToOneType.isDirty(ManyToOneType.java:370)
	at org.hibernate.type.ComponentType.isDirty(ComponentType.java:280)
	at org.hibernate.type.TypeHelper.findDirty(TypeHelper.java:330)
	at org.hibernate.persister.entity.AbstractEntityPersister.findDirty(AbstractEntityPersister.java:4768)
	at org.hibernate.event.internal.DefaultFlushEntityEventListener.dirtyCheck(DefaultFlushEntityEventListener.java:586)
	at org.hibernate.event.internal.DefaultFlushEntityEventListener.isUpdateNecessary(DefaultFlushEntityEventListener.java:249)
	at org.hibernate.event.internal.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:174)
	at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:107)
	at org.hibernate.event.internal.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:229)
	at org.hibernate.event.internal.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:93)
	at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:39)
	at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:107)
	at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1407)
	... 9 more
2023-09-17 14:10:40.855  INFO 1896 --- [           main] org.hibernate.orm.connections.pooling    : HHH10001008: Cleaning up connection pool [jdbc:h2:tcp://localhost/~/test]

Process finished with exit code 0

 

예외 원인을 읽어보니 unsaved trasient instance - save the trasient instance before flushing  문구가 있다. 해당 예외는 영속성 컨텍스트와 관련된 문제이다. Entity 객체를 생성하고 영속성 컨텍스트에 저장하지 않은 상태로 DB에 저장하려고 했기 때문에 문제가 발생했다. 

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오류가 발생한 이유

PhoneNumber 임베디드 타입에서 PhoneServiceProvider 엔티티를 참조하고 있다. 그리고 이 Embedded 타입을 Member 엔티티에서 다루고 있다. Member 엔티티에서 PhoneNumber 임베디드 타입에 값을 매핑해주고 영속성 컨텍스트에 persist를 했다. 여기서 예외가 발생하는데, 그 이유는 PhoneServiceProvider를 영속화시키지 않고 PhoneNumber 임베디드 타입에서 다루었고 이를 Member 엔티티에서 그대로 영속화시켰기 때문이다. 코드를 통해 알아보자.

Member - Entity

@Entity
public class Member {
    @Id
    @GeneratedValue
    @Column(name = "MEMBER_ID")
    private Long id;
    
    private String name;
    private int age;

    @Embedded
    private Address address;

    @Embedded
    private Period period;

    @Embedded
    private PhoneNumber phoneNumber;

    // Getter, Setter
}

PhoneServiceProvider - Entity

@Entity
public class PhoneServiceProvider {

    @Id
    @GeneratedValue
    private Long id;

    public Long getId() {
        return id;
    }
    
    // Getter
}

PhoneNumber - Embedded 타입

@Embeddable
public class PhoneNumber {

    private String areaCode;
    private String localNumber;

    @ManyToOne
    private PhoneServiceProvider provider;
    
    // Getter, 생성자
}

영속화 과정 

PhoneNumber의 생성자를 보면 영속화 되지 않은 provider를 넘겨주었다. 이 PhoneNumber를 Member 엔티티에 저장하고 영속화시켰다. PhoneServiceProvider를 영속화시키지 않고 Member 엔티티를 영속화시키기 때문에 예외가 발생할 수 밖에 없다.

이를 해결하기 위해서 PhoneServiceProvider를 영속화 시켜주면 된다.

Address address = new Address("city1", "street1", "zipcode1");
Period period = new Period(new Date(), new Date());

PhoneServiceProvider provider = new PhoneServiceProvider();
//            em.persist(provider);
PhoneNumber phoneNumber = new PhoneNumber("areaCode1", "localNumber1", provider);

Member member = new Member();
member.setAddress(address);
member.setPeriod(period);
member.setPhoneNumber(phoneNumber);
member.setName("사용자1");
member.setAge(99);
em.persist(member);

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결론

Entity를 영속화 시키고 사용하자!