인프런 커뮤니티 질문&답변

[질문 내용]

MemberRepositoryTest 실행 시 자꾸만 오류가 나네요....... 어찌 해야할지 ㅠ

오류 :

java.lang.NullPointerException: Cannot invoke "org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(java.sql.SQLException, String)" because the return value of "org.hibernate.resource.transaction.backend.jdbc.internal.JdbcIsolationDelegate.sqlExceptionHelper()" is null

at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcIsolationDelegate.delegateWork(JdbcIsolationDelegate.java:116) ~[hibernate-core-6.5.2.Final.jar:6.5.2.Final]

JdbcIsolationDelegate.java:116

at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.getJdbcEnvironmentUsingJdbcMetadata(JdbcEnvironmentInitiator.java:290) ~[hibernate-core-6.5.2.Final.jar:6.5.2.Final]

jpashop/src/main/resources/application.yml

spring:
  datasource:
    url: jdbc:h2:tcp://localhost/~/jpashop;MVCC=true
    username: sa
    password:
    driver-class-name: org.h2.Driver

jpa:
  database-platform: org.hibernate.dialect.H2Dialect
  hibernate:
    ddl-auto: create #Application 실행 시점에 Entity 삭제 & 재생성
  properties:
    hibernate:
      show_sql: true #생성한 SQL 이 다 보임 :) System out 을 통해 출력.
      format_sql: true

logging:
  level:
    org.hibernate.SQL: debug #sql 을 전부 DEBUG 모드로 남긴다는 뜻. Logger 를 통해.

server:
  port: 8092

MemberRepository.java

package jpabook.jpashop;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.springframework.stereotype.Repository;

@Repository //DAO 랑 그냥 똑같은거
public class MemberRepository {
    
    @PersistenceContext
    private EntityManager em; //starter-jpa-start 에 포함!

    // EntityManagerFactory ENTITY_MANAGER_FACTORY = Persistence.createEntityManagerFactory("JPA_DEMO");//
    // EntityManager em = ENTITY_MANAGER_FACTORY.createEntityManager();

    public Long save(Member member) {
        // System.out.println("em:: "+em.toString());
        System.out.println("save");
        em.persist(member); //영속성. 영원히 저장한다 (=DB SAVE)
        return member.getId();
    } //커맨드와 쿼리를 분리하는 정책 설계때문에 Id 만 리턴한다구 함

    public Member find(Long id) {
        System.out.println("find");
        return em.find(Member.class, id);

    }
    
}

MemberRepositoryTest.java

package jpabook.jpashop;

import org.assertj.core.api.Assertions;
import org.junit.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 org.junit.Before;    

@RunWith(SpringRunner.class)
@SpringBootTest
public class MemberRepositoryTest {

    @Autowired MemberRepository memberRepository;
        
    @Test
    @Transactional
    public void test() throws Exception{

        //given
        Member member = new Member();
        member.setUsername("memberA");
        
        System.out.println(member.toString());

        //when
        Long saveId = memberRepository.save(member);
        Member findMember = memberRepository.find(saveId);

        //then
        System.out.println("Then");
        Assertions.assertThat(findMember.getId()).isEqualTo(findMember.getId());

        
    }
}