인프런 커뮤니티 질문&답변

[질문 내용]
maven이 아니라 gradle로 시도를 해보고 싶어서

스프링부트로 생성하여 진행을 해봤는데

em.persist(member);를 실행할때 에러가 발생하는데

도저히 원인을 못찾겠는데 혹시 어떤 문제인지 아시나요?

package com.example.demo.entity;

import jakarta.persistence.Entity;
import jakarta.persistence.Id;

@Entity
public class Member {
	@Id
	private Long id;
	
	private String name;

	public Long getId() {
		return id;
	}

	public void setId(Long id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import com.example.demo.entity.Member;

import jakarta.persistence.EntityManager;
import jakarta.persistence.EntityManagerFactory;
import jakarta.persistence.EntityTransaction;
import jakarta.persistence.Persistence;

@SpringBootApplication
public class StudySpringJpaApplication {

	public static void main(String[] args) {
		SpringApplication.run(StudySpringJpaApplication.class, args);
		
		EntityManagerFactory emf = Persistence.createEntityManagerFactory("hello"); //애플리케이션 전체 공유 (persistence.xml 참조)
		EntityManager em = emf.createEntityManager(); //한번 쓰고 버려야함, 쓰레드간 공유하지 않음
		EntityTransaction tx = em.getTransaction(); //조회를 제외한 DML 작업시 필수로 사용
		tx.begin();
		
		try {
			Member member = new Member();
			member.setId(1L);
			member.setName("memberA");
			
			em.persist(member);
			
			tx.commit();
		} catch (Exception e) {
			e.printStackTrace();
			tx.rollback();
			System.out.println("=== ROLLBACK 진행 ===");
		} finally {
			em.close();
		}
		
		emf.close();
	}

}

 <?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.2"
             xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_2.xsd">
    <!--  EntityManagerFactory 생성 시 사용되는 persistence name -->
    <persistence-unit name="hello">
        <class>com.example.demo.entity.Member</class>
        <properties>
            <!-- 필수 속성 -->
            <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver"/>
            <property name="javax.persistence.jdbc.user" value="root"/>
            <property name="javax.persistence.jdbc.password" value="비밀번호"/>
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3307/jpa?characterEncoding=UTF-8&amp;serverTimezone=UTC"/>

            <!-- 하이버네이트 사용 시 다른 DB에서 MySQL 문법을 사용 가능하도록 변경.-->
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL57Dialect"/>
            <!-- 콘솔에 SQL 출력 여부 -->
            <property name="hibernate.show_sql" value="true"/>
            <!-- 가독성 높여주는 formatting 여부 -->
            <property name="hibernate.format_sql" value="true"/>
            <!-- Comment 확인 여부 -->
            <property name="hibernate.use_sql_comments" value="true"/>
        </properties>
    </persistence-unit>
</persistence>

에러는 다음과 같이 발생합니다.

jakarta.persistence.PersistenceException: Converting `org.hibernate.property.access.spi.PropertyAccessException` to JPA `PersistenceException` : Error accessing field [private java.lang.Long com.example.demo.entity.Member.id] by reflection for persistent property [com.example.demo.entity.Member#id] : com.example.demo.entity.Member@1bc6c7f0
	at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:165)
	at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:175)
	at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:182)
	at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:743)
	at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:721)
	at com.example.demo.StudySpringJpaApplication.main(StudySpringJpaApplication.java:29)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
Caused by: org.hibernate.property.access.spi.PropertyAccessException: Error accessing field [private java.lang.Long com.example.demo.entity.Member.id] by reflection for persistent property [com.example.demo.entity.Member#id] : com.example.demo.entity.Member@1bc6c7f0
	at org.hibernate.property.access.spi.GetterFieldImpl.get(GetterFieldImpl.java:48)
	at org.hibernate.metamodel.mapping.internal.BasicEntityIdentifierMappingImpl.getIdentifier(BasicEntityIdentifierMappingImpl.java:148)
	at org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier(AbstractEntityPersister.java:5269)
	at org.hibernate.persister.entity.AbstractEntityPersister.isTransient(AbstractEntityPersister.java:4856)
	at org.hibernate.engine.internal.ForeignKeys.isTransient(ForeignKeys.java:293)
	at org.hibernate.event.internal.EntityState.getEntityState(EntityState.java:59)
	at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:93)
	at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:53)
	at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:107)
	at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:737)
	... 7 more
Caused by: java.lang.IllegalArgumentException: Can not set java.lang.Long field com.example.demo.entity.Member.id to com.example.demo.entity.Member
	at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167)
	at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171)
	at java.base/jdk.internal.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:58)
	at java.base/jdk.internal.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36)
	at java.base/java.lang.reflect.Field.get(Field.java:425)
	at org.hibernate.property.access.spi.GetterFieldImpl.get(GetterFieldImpl.java:44)
	... 16 more
=== ROLLBACK 진행 ===