18. 스프링 JDBC Template

JdbcTemplate을 사용하여 db연동을 하여 테스트를 돌려보았다.

 

스프링 JdbcTemplate과 MyBatis 같은 라이브러리는

JDBC API에서 본 반복 코드를 대부분 제거해준다.

하지만 SQL은 직접 작생해야 한다.

 

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;

    @Autowired //  생성자 하나기에 생략가능
    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",memberRowMapper());
    }

    private RowMapper<Member> memberRowMapper(){
        return (rs, rowNum) -> {
            Member member = new Member();
            member.setId(rs.getLong("id"));
            member.setName(rs.getString("name"));
            return member;
        };
    }
}

package hello.hellospring;

import hello.hellospring.repository.JdbcMemberRepository;
import hello.hellospring.repository.JdbcTemplateMemberRepository;
import hello.hellospring.repository.MemberRepository;
import hello.hellospring.repository.MemoryMemberRepository;
import hello.hellospring.service.MemberService;
import org.springframework.beans.factory.annotation.Configurable;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;

@Configuration
public class SpringConfig {

    private DataSource dataSource;

    public SpringConfig(DataSource dataSource){
        this.dataSource = dataSource;
    }

    @Bean
    public MemberService memberService(){
        return new MemberService(memberRepository());
    }

    @Bean
    public MemberRepository memberRepository(){
        return new JdbcTemplateMemberRepository(dataSource);
    }
}

SpringConfig의 memberRepository()에서

repository/JdbcTemplateMemberRepository(dataSource)를 

반환하여 테스트를 돌려보았더니

성공하였다!

정보처리기사 공부하며 나온 디자인 패턴이라는 내용에

깊이있게 들어가고 싶어졌다. 저번시간에도 그렇고 Template패턴이라는 것이

나오고 또한 Singleton패턴이라는 말도 자주 나온다

다음에 꼭 디자인패턴쪽도 공부해보아야 겠다!