즉시 로딩과 지연 로딩 강의 2:30 NullPointerException 관련
1
[질문 템플릿]1. 강의 내용과 관련된 질문인가요? (예)2. 인프런의 질문 게시판과 자주 하는 질문에 없는 내용인가요? (예)3. 질문 잘하기 메뉴얼을 읽어보셨나요? (예)[질문 내용]
package hellojpa;
import javax.persistence.*;
public class JpaMain {
public static void main(String[] args) {
EntityManagerFactory emf = Persistence.createEntityManagerFactory("hello");
EntityManager em = emf.createEntityManager();
EntityTransaction tx = em.getTransaction();
tx.begin();
try {
Team team = new Team();
team.setName("teamA");
em.persist(team);
Member member1 = new Member();
member1.setUsername("member1");
member1.setTeam(team);
em.persist(member1);
em.flush();
em.clear();
Member m = em.find(Member.class, member1.getId());
System.out.println("m = " + m.getTeam().getClass());
tx.commit();
} catch (Exception e) {
tx.rollback();
e.printStackTrace();
} finally {
em.close();
}
emf.close();
}
}
위와 같이 강사님의 코드를 그대로 받아쓰고 실행을 하였습니다.
java.lang.NullPointerException
at hellojpa.JpaMain.main(JpaMain.java:30)
Jun 23, 2023 10:53:10 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl stop
INFO: HHH10001008: Cleaning up connection pool [jdbc:h2:tcp://localhost/~/test]위와 같은 에러가 발생하였습니다. team 객체를 생성하였는데 왜 NullPointerException 에러가 발생한 것일까요? 답변주시면 감사하겠습니다!!
답변 1
0
안녕하세요. dev_prao님, 공식 서포터즈 David입니다.
혹시 질문에 올려주신 로그가 오류의 전부인걸까요??
오류 로그 전문을 올려주시면 답변에 큰 도움이 됩니다.
감사합니다.
0
Jun 25, 2023 5:56:53 PM org.hibernate.jpa.internal.util.LogHelper logPersistenceUnitInformation
INFO: HHH000204: Processing PersistenceUnitInfo [
name: hello
...]
Jun 25, 2023 5:56:53 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.3.10.Final}
Jun 25, 2023 5:56:53 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Jun 25, 2023 5:56:53 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.0.4.Final}
Jun 25, 2023 5:56:53 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
Jun 25, 2023 5:56:53 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [org.h2.Driver] at URL [jdbc:h2:tcp://localhost/~/test]
Jun 25, 2023 5:56:53 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {user=sa}
Jun 25, 2023 5:56:53 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
Jun 25, 2023 5:56:53 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 20 (min=1)
Jun 25, 2023 5:56:54 PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.H2Dialect
Hibernate:
drop table Album if exists
Hibernate:
drop table Book if exists
Hibernate:
drop table Member if exists
Hibernate:
drop table MemberProduct if exists
Hibernate:
drop table Movie if exists
Hibernate:
drop table Product if exists
Hibernate:
drop table Team if exists
Hibernate:
drop sequence if exists hibernate_sequence
Jun 25, 2023 5:56:54 PM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection
INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@36c54a56] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode.
Hibernate: create sequence hibernate_sequence start with 1 increment by 1
Hibernate:
create table Album (
id bigint not null,
name varchar(255),
price integer not null,
artist varchar(255),
primary key (id)
)
Hibernate:
create table Book (
id bigint not null,
name varchar(255),
price integer not null,
author varchar(255),
isbn varchar(255),
primary key (id)
)
Hibernate:
create table Member (
MEMBER_ID bigint not null,
INSERT_MEMBER varchar(255),
createdDate timestamp,
UPDATE_MEMBER varchar(255),
lastModifiedDate timestamp,
USERNAME varchar(255),
TEAM_ID bigint,
primary key (MEMBER_ID)
)
Hibernate:
create table MemberProduct (
id bigint not null,
count integer not null,
orderDateTime timestamp,
price integer not null,
MEMBER_ID bigint,
PRODUCT_ID bigint,
primary key (id)
)
Hibernate:
create table Movie (
id bigint not null,
name varchar(255),
price integer not null,
actor varchar(255),
director varchar(255),
primary key (id)
)
Hibernate:
create table Product (
id bigint not null,
name varchar(255),
primary key (id)
)
Jun 25, 2023 5:56:54 PM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection
INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@68ace111] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode.
Hibernate:
create table Team (
TEAM_ID bigint not null,
INSERT_MEMBER varchar(255),
createdDate timestamp,
UPDATE_MEMBER varchar(255),
lastModifiedDate timestamp,
name varchar(255),
primary key (TEAM_ID)
)
Hibernate:
alter table Member
add constraint FKl7wsny760hjy6x19kqnduasbm
foreign key (TEAM_ID)
references Team
Hibernate:
alter table MemberProduct
add constraint FKjnj8ungt7v35y6lfxuxcrjbbr
foreign key (MEMBER_ID)
references Member
Hibernate:
alter table MemberProduct
add constraint FKrgt6jorh7iaec1tae84ljye8c
foreign key (PRODUCT_ID)
references Product
Jun 25, 2023 5:56:54 PM org.hibernate.tool.schema.internal.SchemaCreatorImpl applyImportSources
INFO: HHH000476: Executing import script 'org.hibernate.tool.schema.internal.exec.ScriptSourceInputNonExistentImpl@4fbb001b'
Hibernate:
call next value for hibernate_sequence
Hibernate:
call next value for hibernate_sequence
Hibernate:
/* insert hellojpa.Team
*/ insert
into
Team
(INSERT_MEMBER, createdDate, UPDATE_MEMBER, lastModifiedDate, name, TEAM_ID)
values
(?, ?, ?, ?, ?, ?)
Hibernate:
/* insert hellojpa.Member
*/ insert
into
Member
(INSERT_MEMBER, createdDate, UPDATE_MEMBER, lastModifiedDate, USERNAME, MEMBER_ID)
values
(?, ?, ?, ?, ?, ?)
Hibernate:
select
member0_.MEMBER_ID as MEMBER_I1_3_0_,
member0_.INSERT_MEMBER as INSERT_M2_3_0_,
member0_.createdDate as createdD3_3_0_,
member0_.UPDATE_MEMBER as UPDATE_M4_3_0_,
member0_.lastModifiedDate as lastModi5_3_0_,
member0_.TEAM_ID as TEAM_ID7_3_0_,
member0_.USERNAME as USERNAME6_3_0_
from
Member member0_
where
member0_.MEMBER_ID=?
java.lang.NullPointerException
at hellojpa.JpaMain.main(JpaMain.java:30)
Jun 25, 2023 5:56:54 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl stop
INFO: HHH10001008: Cleaning up connection pool [jdbc:h2:tcp://localhost/~/test]
Process finished with exit code 0실행 시 나오는 코드 전문입니다!
0
오류 전문 감사합니다.
아무래도 실행 가능한 코드로 돌려보고 확인해 보아야 할 것 같습니다:)
아래 가이드를 참고하셔서 프로젝트 공유 부탁드립니다.
실제 동작하는 전체 프로젝트를 압축해서 구글 드라이브로 공유해서 링크를 남겨주세요.
구글 드라이브 업로드 방법은 다음을 참고해주세요.
주의: 업로드시 링크에 있는 권한 문제 꼭 확인해주세요
10
답변 감사합니다 David님. 주말간에 계속 코드를 뜯어보다가 member 클래스의 team team 객체를 생성하고 어노테이션으로 JoinColumn 조건에 nullable과 updatable을 false로 설정해둔 것이 문제였던 것으로 확인했습니다. 감사합니다:)
벌크연산에서 member.getAge 호출 시 영속성 컨텍스트에서 데이터를 가져오는건가요?
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혹시 현재는 ID 데이터 타입이 String이면 안되나요?
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