[Spring Boot] MyBatis 사용법 (DAO)

목차

0. 환경

• windows10
• openjdk version "11" 2018-09-25
• IntelliJ Tool
• Spring Boot 2.5.6
• Gradle Project 
• MyBatis + Mysql + HikariCP를 이용해 DB(Mysql) 연동할 프로젝트입니다.

1. 도메인 생성

• com/test/api/domain/Test.java

package com.test.api.domain;

import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
public class Test {

    private String column1;
    private String column2;
}

2. DAO 생성

• com/test/api/repository/TestDao.java (인터페이스)
• com/test/api/repository/TestDaoImpl.java (구현체 클래스)

package com.test.api.repository;

import com.test.api.domain.Test;

public interface TestDao {

    Test test2();
}

package com.test.api.repository;

import com.test.api.domain.Test;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

@Repository
public class TestDaoImpl implements TestDao {

    private final SqlSessionTemplate sqlSession;

    private static final String Namespace = "com.test.api.mapper.TestMapper";

    @Autowired
    TestDaoImpl(SqlSessionTemplate sqlSession){
        this.sqlSession = sqlSession;
    }

    @Override
    public Test test2() {
        return sqlSession.selectOne(Namespace+".test2");
    }
}

3. Mapper xml 생성

• resources/mapper/TestMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="TestMapper">

    <select id="test2" resultType="Test">
        SELECT 3 AS 'column1', 4 AS 'column2'
    </select>

</mapper>

4. 서비스 생성

• com/test/api/service/TestService.java

package com.test.api.service;

import com.test.api.domain.Test;
import com.test.api.repository.TestDao;
import com.test.api.repository.TestDaoImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class TestService {

    private final TestDao testDao;

    @Autowired
    public TestService(TestDaoImpl testDao){
        this.testDao = testDao;
    }

    public Test test2() throws Exception {
        return testDao.test2();
    }
}

5. 컨트롤러 생성

• com/test/api/controller/TestController.java

package com.test.api.controller;

import com.test.api.domain.Test;
import com.test.api.service.TestService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {

    private final TestService testService;

    @Autowired
    public TestController(TestService testService){
        this.testService = testService;
    }

    @GetMapping(value = "/test2")
    public Test test2() throws Exception {
        return testService.test2();
    }

}

6. 테스트

• Spring Boot를 실행 후 브라우저를 이용해 해당 컨트롤러 경로로 접속해 봅니다.