JAVA 8 / Maven / h2
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.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 {
/* 저장 */
// Member member = new Member();
// member.setId(2L);
// member.setName("hello2");
// em.persist(member);
/* 수정 */
// Member member = em.find(Member.class, 1l);
// member.setName("newName");
// 트랜잭션 직전에 변경사항을 점검하고 커밋을 날림
// persist를 할 필요가 없음
/* 각종 조회 */
List<Member> resultList = em.createQuery("select m from Member as m", Member.class).setFirstResult(1)
.setMaxResults(3).getResultList();
tx.commit();
} catch (Exception e) {
tx.rollback();
} finally {
em.close();
}
emf.close();
}
}