스프링MVC 입문21

스프링 JdbcTemplate

• 순수 Jdbc와 동일한 환경설정을 하면 됨
• 스프링 JdbcTemplate과 MyBatis 같은 라이브러리는 JDBC API에서 본 반복 코드를 대부분 제거해줌
• SQL은 직접 작성해야 함

 

JdbcTemplateMemberRepository

package com.danny.learningspring.repository;

import com.danny.learningspring.domain.Member;
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.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;

public class JdbcTemplateMemberRepository implements MemberRepository{

    private final JdbcTemplate jdbcTemplate;

    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;
        };
    }

}

• 생성자가 하나일 때는 @Autowired를 생략해도 됨
• option + enter -- replace with lamda
• RowMapper -- 원하는 형태의 결과값을 반환할 수 있음
  • SELECT로 나온 여러개의 값을 반환할 수 있음
  • 사용자가 원하는 형태로도 얼마든지 받을 수 있음 

 

SpringConfig

package com.danny.learningspring;

import com.danny.learningspring.repository.JdbcMemberRepository;
import com.danny.learningspring.repository.JdbcTemplateMemberRepository;
import com.danny.learningspring.repository.MemberRepository;
import com.danny.learningspring.repository.MemoryMemberRepository;
import com.danny.learningspring.service.MemberService;
import lombok.RequiredArgsConstructor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;

@Configuration
@RequiredArgsConstructor
public class SpringConfig {


    private final DataSource dataSource;

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

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

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

• Repository 교체

 

MemberServiceIntegrationTest 실행 결과

Passed