기존 jdbc 라이브러리 대신 jpa라이브러리를 설정합니다. 설정 뒤에는 코끼리 아이콘을 클릭하여 라이브러리를 끌어와 설치해줍니다.
2. application.properties 설정
spring.jpa,.show-sql=true 는 jpa가 수행하는 sql을 볼 수 있도록 하는 옵션이고,
spring.jpa.hibernate.ddl-auto=none 은 회원 객체를 확인할 때 테이블을 자동 생성하는 기능은 끄고 시작하는 것입니다. 이번 예제에서는 테이블을 생성해 놓았으므로 none으로 합니다. none대신 create로 할 경우 테이블 생성까지도 자동으로 해 줍니다.
3. Member 클래스 코드 수정
@Entity : JPA가 관리하는 Entity임을 인식시켜줌
@Id: PK를 인식시켜줌
@GeneratedValue: 자동 생성되는 값임을 인식시켜줌
package hello.hellospring.domain;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity
public class Member {
@Id @GeneratedValue(strategy = GenerationType.IDENTITY)
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;
}
}
4. JpmMemberRepository 클래스 구성
JPQL이라는 문법으로 Query를 작성합니다.
package hello.hellospring.repository;
import hello.hellospring.domain.Member;
import javax.persistence.EntityManager;
import java.util.List;
import java.util.Optional;
public class JpaMemberRepository implements MemberRepository{
private final EntityManager em; // 스프링 부트가 자동 생성함. 데이터 소스를 들고있음.
public JpaMemberRepository(EntityManager em) {
this.em = em;
}
@Override
public Member save(Member member) {
em.persist(member);
return member;
}
@Override
public Optional<Member> findById(Long id) {
Member member = em.find(Member.class, id);
return Optional.ofNullable(member);
}
@Override
public Optional<Member> findByName(String name) {
List<Member> result = em.createQuery("select m from Member m where m.name=:name", Member.class)
.setParameter("name", name)
.getResultList();
return result.stream().findAny();
}
@Override
public List<Member> findAll() {
return em.createQuery("select m from Member m", Member.class)
.getResultList();
}
}
5. MemberService 클래스 수정
클래스 선언부 앞에 @Transactional 이라는 annotation을 붙여줍니다.
package hello.hellospring.service;
import hello.hellospring.domain.Member;
import hello.hellospring.repository.MemberRepository;
import hello.hellospring.repository.MemoryMemberRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import java.util.List;
import java.util.Optional;
@Transactional
public class MemberService {
private final MemberRepository memberRepository;
public MemberService(MemberRepository memberRepository){
this.memberRepository = memberRepository;
}
/*
회원 가입 이하 생략
*/
6. SpringConfig 수정
위에서 구축한 JpaMemberRepository를 등록해줍니다.
package hello.hellospring;
import hello.hellospring.repository.JdbcTemplateMemberRepository;
import hello.hellospring.repository.JpaMemberRepository;
import hello.hellospring.repository.MemberRepository;
import hello.hellospring.repository.MemoryMemberRepository;
import hello.hellospring.service.MemberService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.persistence.EntityManager;
import javax.sql.DataSource;
@Configuration
public class SpringConfig {
private EntityManager em;
@Autowired
public SpringConfig(EntityManager em){
this.em = em;
}
// private DataSource dataSource;
//
// @Autowired
// public SpringConfig(DataSource dataSource){
// this.dataSource = dataSource;
// }
@Bean
public MemberService memberService(){
return new MemberService(memberRepository());
}
@Bean
public MemberRepository memberRepository(){
//return new MemoryMemberRepository();
//return new JdbcTemplateMemberRepository(dataSource);
return new JpaMemberRepository(em);
}
}
package hello.hellospring.repository;
import hello.hellospring.domain.Member;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
import org.springframework.jdbc.core.simple.SimpleJdbcInsert;
import javax.sql.DataSource;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
public class JdbcTemplateMemberRepository implements MemberRepository{
private final JdbcTemplate jdbcTemplate;
//Datasource 자동으로 인젝션
@Autowired // 생성자가 1개일 경우 @Autowired는 생략 가능
public JdbcTemplateMemberRepository(DataSource dataSource){
jdbcTemplate = new JdbcTemplate(dataSource);
}
@Override
public Member save(Member member) {
SimpleJdbcInsert jdbcInsert = new SimpleJdbcInsert(jdbcTemplate);
jdbcInsert.withTableName("member").usingGeneratedKeyColumns("id");
Map<String, Object> parameters = new HashMap<>();
parameters.put("name", member.getName());
Number key = jdbcInsert.executeAndReturnKey(new MapSqlParameterSource(parameters));
member.setId(key.longValue());
return member;
}
@Override
public Optional<Member> findById(Long id) {
List<Member> result = jdbcTemplate.query("select * from member where id = ?",memberRowMapper(), id);
return result.stream().findAny();
}
@Override
public Optional<Member> findByName(String name) {
List<Member> result = jdbcTemplate.query("select * from member where name = ?",memberRowMapper(), name);
return result.stream().findAny();
}
@Override
public List<Member> findAll() {
return jdbcTemplate.query("select * from member where name = ?",memberRowMapper());
}
private RowMapper<Member> memberRowMapper(){
return (rs, rowNum) -> {
Member member = new Member();
member.setId(rs.getLong("id"));
member.setName(rs.getString("name"));
return member;
};
}
}
