MyBatis API 활용

●MyBatis - SQL Mapping Framework for Java

java에서 xml파일을 접근해야함(mapping) sql분리하기(유지보수 용이함)

 

 

*Java에서 xml로 되어있는파일(mapper file)에 sql을 쓰고싶으면 id이름을 찾아가서  

xml로 뺄수있음.

 

MyBatis내부에 JDBC를 쓰는것이라 JDBC API도 필요하다

 

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MyBatis환경설정

The configuration XML file - 환경설정파일  

SQL만 모아져있는파일 - mapper파일

database접근정보 알려줘야함?

 

core of the MyBatis system    core파일

xml파일로

  <configuration>

     <environments>

           JDBC에 연결할수있도록~~~~

 

SQL에있는 xml파일을 mappers로 연결

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●환경설정파일(config.xml)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <properties resource="kr/smhrd/mybatis/db.properties"/>
  <environments default="development">
    <environment id="development">
      <transactionManager type="JDBC"/>
      <dataSource type="POOLED">
        <property name="driver" value="${driver}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
      </dataSource>
    </environment>
  </environments>
  <mappers>
    <mapper resource="kr/smhrd/mybatis/MemberMapper.xml"/>
  </mappers>
</configuration>

 

SqlSessionFactory 안에 SqlSession들

 

★ConnectionPool -  Sql세션들 (connection객체들)을 모아둔 pool을미리만들어놓고 필요할때마다 db에서재활용

                                                                      (MyBatis는 이미 만들어져있음)

 

 

●mapper.xml 파일 환경설정 (여러개 만들수있음)

<?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="org.mybatis.example.BlogMapper">
  <select id="selectBlog" resultType="Blog">
    select * from Blog where id = #{id}
  </select>
</mapper>

 

EL -  ${ }

jQuery  -  $( )

MyBatis  -  #{ }

 

 

 

●db.properties

driver=oracle.jdbc.driver.OracleDriver
url=jdbc:oracle:thin:@127.0.0.1:1521:XE
username=hr
password=hr

 

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●MemberDAOImpl

// 초기화 블럭(한번만 실행하는 블럭)
	static {
		String resource = "kr/smhrd/mybatis/config.xml";
		InputStream inputStream = Resources.getResourceAsStream(resource);
		SqlSessionFactory sqlSessionFactory =
		new SqlSessionFactoryBuilder().build(inputStream);
	}

InputStream - 입력스트림(입력하는 빨대) <-> Resources.get xml파일

SqlSessionFactoryBuilder().build(inputStream) - xml읽어서 build메소드로 Connection통해 만들기

 

 

▼예외처리 해주기

 

private static SqlSessionFactory sqlSessionFactory;
	// 초기화 블럭(한번만 실행하는 블럭)
	static {
		String resource = "kr/smhrd/mybatis/config.xml";
		InputStream inputStream;
		try {
			inputStream = Resources.getResourceAsStream(resource);
			sqlSessionFactory =new SqlSessionFactoryBuilder().build(inputStream);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	

inputStream에 예외처리도 해줘야하고,

try문안에 SqlSessionFactory가있으면 뭔가가 안돼서 try문 밖에서 private static으로 선언해준다.

 

 

 

●MemberDAOImpl

@Override
	public List<MemberVO> memberList() {
		SqlSession session = sqlSessionFactory.openSession();
		//SQL문장(select ~,...) + MemberVO + ArrayList(X, - selectList())
		List<MemberVO> list = session.selectList("memberList");
		session.close();
		return list;
	}

get과같은게 openSession

openSession했으면 session.close(반납개념)해야함.

 

 

 

●MemberMapper.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="kr.smhrd.mybatis.MemberMapper">
<select id="memberList" resultType="MemberVO">
    select * from memiot
</select>
    
</mapper>

위에서 말했듯이 mapper file에 sql을 쓰고싶으면 id이름을 찾아가서  xml로 뺄수있다.

 

 

 

 

●config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <properties resource="kr/smhrd/mybatis/db.properties"/>
    <typeAliases>
        <typeAlias type="kr.smhrd.model.MemberVO" alias="MemberVO"/>
    </typeAliases>

MemberMapper.xml에서 alias쓸려면 config(환경설정)에서 alias 설정해주면 된다.

 

 

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● MemberDAOImpl.java (최종)

//myBatis
public class MemberDAOImpl implements MemberDAO{
	private static SqlSessionFactory sqlSessionFactory;
	// 초기화 블럭(한번만 실행하는 블럭)
	static {
		String resource = "kr/smhrd/mybatis/config.xml";
		InputStream inputStream;
		try {
			inputStream = Resources.getResourceAsStream(resource);
			sqlSessionFactory =new SqlSessionFactoryBuilder().build(inputStream);
		} catch (IOException e) {
			e.printStackTrace();
		}
		
	}
	
	@Override
	public List<MemberVO> memberList() {
		SqlSession session = sqlSessionFactory.openSession();
		//SQL문장(select ~,...) + MemberVO + ArrayList(X, - selectList())
		List<MemberVO> list = session.selectList("memberList");
		session.close();
		return list;
	}

	@Override
	public int memberInsert(MemberVO vo) {
		SqlSession session = sqlSessionFactory.openSession();
		int cnt = session.insert("memberInsert",vo);
		session.commit(); //완료
		session.close(); //반납
		return cnt;
	}

	@Override
	public int memberDelete(int num) {
		SqlSession session = sqlSessionFactory.openSession();
		int cnt = session.delete("memberDelete",num);
		session.commit(); //완료
		session.close(); //반납
		return cnt;
	}

	@Override
	public MemberVO memberContent(int num) {
		SqlSession session = sqlSessionFactory.openSession();
		MemberVO vo = session.selectOne("memberContent",num);
		session.close(); //반납
		return vo;

	}

	@Override
	public int memberUpdate(MemberVO vo) {
		SqlSession session = sqlSessionFactory.openSession();
		int cnt = session.update("memberUpdate",vo);
		session.commit(); //완료
		session.close(); //반납
		return cnt;
	}
	
}

insert는 select와달리 DB의 값을 변경하기 때문에 session.commit을 추가로 해줘야함

delete도 commit해야하지만 int num으로

content도 num을 받고 commit은 사용하지않아도된다.

update는 commit해야하고 MemberVO vo로 받아온다

 

 

 

 

● MemberMapper.xml (최종)

<?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="kr.smhrd.mybatis.MemberMapper">
   <select id="memberList" resultType="MemberVO">
    select * from memiot
   </select>
   
   <insert id="memberInsert" parameterType="MemberVO">
   insert into memiot values(num_seq.nextval,
   #{id},
   #{pass},
   #{mname},
   #{mage},
   #{memail},
   #{mtel})
   </insert>
   
   <delete id="memberDelete" parameterType="Integer">
       delete from memiot where num=#{num}
   </delete>
   
   <select id="memberContent" parameterType="Integer" resultType="MemberVO">
       select * from memiot where num=#{num}
   </select>
   
   <update id="memberUpdate" parameterType="MemberVO" >
     UPDATE memiot SET mage=#{mage}, memail=#{memail}, mtel=#{mtel} WHERE num=#{num}
     </update>
</mapper>

MemberDAOImpl.java (최종) 에 맞게 sql문을 mybatis  #{ }이용해 사용하고

각 id , parameterType ,  resultType 를 잘 성정해야한다.