ch4 10. 댓글 기능 구현(1) - DAO 작성

1. 댓글 기능 구현 순서

1) DB 테이블 생성

2) Mapper XML 작성

3) DAO 작성 & 테스트

4) Service 작성 & 테스트 

5) 컨트롤러 작성 & 테스트

--> 백앤드

6) 뷰(UI) 작성 & 테스트

--> 프론트앤드

 

1) DB 테이블 생성

데이터 하나 삽입 후 테이블 조회

 

 

 

2) Mapper XML 작성 (commentMapper.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="com.fastcampus.ch4.dao.CommentMapper">
    <delete id="deleteAll" parameterType="int">
        DELETE FROM comment
        WHERE  bno = #{bno}
    </delete>

    <select id="count" parameterType="int" resultType="int">
        SELECT count(*) FROM comment
        WHERE  bno = #{bno}
    </select>

    <delete id="delete" parameterType="map">
        DELETE FROM comment WHERE cno = #{cno} AND commenter = #{commenter}
    </delete>

    <insert id="insert" parameterType="CommentDto">
        INSERT INTO comment
            (bno, pcno, comment, commenter, reg_date, up_date)
        VALUES
            (#{bno}, #{pcno}, #{comment}, #{commenter}, now(), now())
    </insert>

    <select id="selectAll" parameterType="int" resultType="CommentDto">
        SELECT cno, bno, pcno, comment, commenter, reg_date, up_date
        FROM comment
        WHERE bno = #{bno}
        ORDER BY reg_date ASC, cno ASC
    </select>

    <select id="select" parameterType="int" resultType="CommentDto">
        SELECT cno, bno, pcno, comment, commenter, reg_date, up_date
        FROM comment
        WHERE cno = #{cno}
    </select>

    <update id="update" parameterType="CommentDto">
        UPDATE comment
        SET comment = #{comment}
          , up_date = now()
        WHERE cno = #{cno} and commenter = #{commenter}
    </update>
</mapper>

작성한 다음 쿼리창에 넣어서  돌려봐야 한다. 

 

 

3) DAO 작성 & 테스트

- mapper.xml에 있는 sql들을 하나씩 불러오는 함수들 생성

이름을 CommentDao에서 인터페이스 추출 시 CommentDaoImpl로 해서 추출.

 

[CommentDaoImpl]

package com.fastcampus.ch4.dao;

import com.fastcampus.ch4.domain.CommentDto;
import org.apache.ibatis.session.*;
import org.springframework.beans.factory.annotation.*;
import org.springframework.stereotype.*;

import java.util.*;

@Repository
public class CommentDaoImpl implements CommentDao {
    @Autowired
    private SqlSession session;
    private static String namespace = "com.fastcampus.ch4.dao.CommentMapper.";

    @Override
    public int count(Integer bno) throws Exception {
        return session.selectOne(namespace+"count", bno);
    } // T selectOne(String statement)

    @Override
    public int deleteAll(Integer bno) {
        return session.delete(namespace+"deleteAll", bno);
    } // int delete(String statement)

    @Override
    public int delete(Integer cno, String commenter) throws Exception {
        Map map = new HashMap();
        map.put("cno", cno);
        map.put("commenter", commenter);
        return session.delete(namespace+"delete", map);
    } // int delete(String statement, Object parameter)

    @Override
    public int insert(CommentDto dto) throws Exception {
        return session.insert(namespace+"insert", dto);
    } // int insert(String statement, Object parameter)

    @Override
    public List<CommentDto> selectAll(Integer bno) throws Exception {
        return session.selectList(namespace+"selectAll", bno);
    } // List<E> selectList(String statement)

    @Override
    public CommentDto select(Integer cno) throws Exception {
        return session.selectOne(namespace + "select", cno);
    } // T selectOne(String statement, Object parameter)

    @Override
    public int update(CommentDto dto) throws Exception {
        return session.update(namespace+"update", dto);
    } // int update(String statement, Object parameter)
}

[CommentDao]

package com.fastcampus.ch4.dao;

import com.fastcampus.ch4.domain.CommentDto;

import java.util.List;

public interface CommentDao {
    int count(Integer bno) throws Exception // T selectOne(String statement)
    ;

    int deleteAll(Integer bno) // int delete(String statement)
    ;

    int delete(Integer cno, String commenter) throws Exception // int delete(String statement, Object parameter)
    ;

    int insert(CommentDto dto) throws Exception // int insert(String statement, Object parameter)
    ;

    List<CommentDto> selectAll(Integer bno) throws Exception // List<E> selectList(String statement)
    ;

    CommentDto select(Integer cno) throws Exception // T selectOne(String statement, Object parameter)
    ;

    int update(CommentDto dto) throws Exception // int update(String statement, Object parameter)
    ;
}

 

- CommentDto 생성

DB의 열 보면서 작성

bno, pcno, comment, commenter 생성자 생성.

전부 다 getter, setter, toString 생성

equals에 Date 변수 빼고 생성, 이후 next

package com.fastcampus.ch4.domain;

import java.util.Date;
import java.util.Objects;

public class CommentDto {
    private Integer cno;
    private Integer bno;
    private Integer pcno;
    private String comment;
    private String commenter;
    private Date reg_date;
    private Date up_date;

    public CommentDto() {}
    public CommentDto(Integer bno, Integer pcno, String comment, String commenter) {
        this.bno = bno;
        this.pcno = pcno;
        this.comment = comment;
        this.commenter = commenter;
    }

    public Integer getCno() {
        return cno;
    }

    public void setCno(Integer cno) {
        this.cno = cno;
    }

    public Integer getBno() {
        return bno;
    }

    public void setBno(Integer bno) {
        this.bno = bno;
    }

    public Integer getPcno() {
        return pcno;
    }

    public void setPcno(Integer pcno) {
        this.pcno = pcno;
    }

    public String getComment() {
        return comment;
    }

    public void setComment(String comment) {
        this.comment = comment;
    }

    public String getCommenter() {
        return commenter;
    }

    public void setCommenter(String commenter) {
        this.commenter = commenter;
    }

    public Date getReg_date() {
        return reg_date;
    }

    public void setReg_date(Date reg_date) {
        this.reg_date = reg_date;
    }

    public Date getUp_date() {
        return up_date;
    }

    public void setUp_date(Date up_date) {
        this.up_date = up_date;
    }

    @Override
    public String toString() {
        return "CommentDto{" +
                "cno=" + cno +
                ", bno=" + bno +
                ", pcno=" + pcno +
                ", comment='" + comment + '\'' +
                ", commenter='" + commenter + '\'' +
                ", reg_date=" + reg_date +
                ", up_date=" + up_date +
                '}';
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        CommentDto that = (CommentDto) o;
        return Objects.equals(cno, that.cno) && Objects.equals(bno, that.bno) && Objects.equals(pcno, that.pcno) && Objects.equals(comment, that.comment) && Objects.equals(commenter, that.commenter);
    }

    @Override
    public int hashCode() {
        return Objects.hash(cno, bno, pcno, comment, commenter);
    }
}

 

 

- 테스트 생성

mybatis-configxml 별칭 추가

package com.fastcampus.ch4.dao;

import com.fastcampus.ch4.domain.*;
import org.junit.*;
import org.junit.runner.*;
import org.springframework.beans.factory.annotation.*;
import org.springframework.test.context.*;
import org.springframework.test.context.junit4.*;

import java.util.*;

import static org.junit.Assert.*;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"file:src/main/webapp/WEB-INF/spring/root-context.xml"})
public class CommentDaoImplTest {
    @Autowired
    CommentDao commentDao;

    @Test
    public void count() throws Exception {
        commentDao.deleteAll(1); // 게시물 1번 댓글 다 지움
        assertTrue(commentDao.count(1)==0);
    }

    @Test
    public void delete() throws Exception {
        commentDao.deleteAll(1);
        CommentDto commentDto = new CommentDto(1, 0, "comment", "asdf");
        assertTrue(commentDao.insert(commentDto)==1);
        assertTrue(commentDao.count(1)==1);
    }

    @Test
    public void insert() throws Exception {
        commentDao.deleteAll(1);
        CommentDto commentDto = new CommentDto(1, 0, "comment", "asdf");
        assertTrue(commentDao.insert(commentDto)==1);
        assertTrue(commentDao.count(1)==1);

        commentDto = new CommentDto(1, 0, "comment", "asdf");
        assertTrue(commentDao.insert(commentDto)==1);
        assertTrue(commentDao.count(1)==2);
    }

    @Test
    public void selectAll() throws Exception {
        commentDao.deleteAll(1);
        CommentDto commentDto = new CommentDto(1, 0, "comment", "asdf");
        assertTrue(commentDao.insert(commentDto)==1);
        assertTrue(commentDao.count(1)==1);

        List<CommentDto> list = commentDao.selectAll(1);
        assertTrue(list.size()==1);

        commentDto = new CommentDto(1, 0, "comment", "asdf");
        assertTrue(commentDao.insert(commentDto)==1);
        assertTrue(commentDao.count(1)==2);

        list = commentDao.selectAll(1);
        assertTrue(list.size()==2);
    }

    @Test
    public void select() throws Exception {
        commentDao.deleteAll(1);
        CommentDto commentDto = new CommentDto(1, 0, "comment", "asdf");
        assertTrue(commentDao.insert(commentDto)==1);
        assertTrue(commentDao.count(1)==1);

        List<CommentDto> list = commentDao.selectAll(1);
        String comment = list.get(0).getComment();
        String commenter = list.get(0).getCommenter();
        assertTrue(comment.equals(commentDto.getComment()));
        assertTrue(commenter.equals(commentDto.getCommenter()));
    }

    @Test
    public void update() throws Exception {
        commentDao.deleteAll(1);
        CommentDto commentDto = new CommentDto(1, 0, "comment", "asdf");
        assertTrue(commentDao.insert(commentDto)==1);
        assertTrue(commentDao.count(1)==1);

        List<CommentDto> list = commentDao.selectAll(1);
        commentDto.setCno(list.get(0).getCno());
        commentDto.setComment("comment2");
        assertTrue(commentDao.update(commentDto)==1);

        list = commentDao.selectAll(1);
        String comment = list.get(0).getComment();
        String commenter = list.get(0).getCommenter();
        assertTrue(comment.equals(commentDto.getComment()));
        assertTrue(commenter.equals(commentDto.getCommenter()));
    }
}

테스트 코드를 돌리면 테스트가 통과함을 확인할 수 있다. 

 

 

4) Service 작성 & 테스트

- CommentService 클래스 생성

댓글이 추가되거나 삭제되면, BoardDao도 영향이 간다. 

DB에서 board를 보면, comment_cnt가 있는데 comment가 추가되면 +1, 지워지면 -1이 되어야한다. 

그래서 CommentService는 BoardDao와 CommentDao 두 개를 다 주입받아야한다. 

 

필드 주입을 할 때 실수로 @Autowired을 빼먹어도 문제를 발견하지 못한다. 

생성자 주입으로 해놓으면, 컴파일 할 때 이 문제를 알 수 있다. 

그래서 필드 주입보다는 생성자 주입을 더 권장한다. 

 

인터페이스 추출 수행.

 

- boardMapper.xml에서 sql문 생성

boardMapper.xml

BoardDaolmpl

 

[CommentServiceImpl]

package com.fastcampus.ch4.service;

import com.fastcampus.ch4.dao.*;
import com.fastcampus.ch4.domain.*;
import org.springframework.beans.factory.annotation.*;
import org.springframework.stereotype.*;
import org.springframework.transaction.annotation.*;

import java.util.*;

@Service
public class CommentServiceImpl implements CommentService {
    // 인스턴스 변수에 주입
//    @Autowired
    BoardDao boardDao;
//    @Autowired
    CommentDao commentDao;

    // 생성자 주입. @Autowired 생략 가능. 생성자 하나일 때 가능
    // 위보단 생성자 주입 사용해서 실수를 줄임.
    @Autowired
    public CommentServiceImpl(CommentDao commentDao, BoardDao boardDao) {
        this.commentDao = commentDao;
        this.boardDao = boardDao;
    }

    @Override
    public int getCount(Integer bno) throws Exception {
        return commentDao.count(bno);
    }


    // 댓글 수 감소와 지우기 둘 다 성공해야함. 예외 발생하면 rollback
    @Override
    @Transactional(rollbackFor = Exception.class)
    public int remove(Integer cno, Integer bno, String commenter) throws Exception {
        int rowCnt = boardDao.updateCommentCnt(bno, -1);
        System.out.println("updateCommentCnt - rowCnt = " + rowCnt);
//        throw new Exception("test");
        rowCnt = commentDao.delete(cno, commenter);
        System.out.println("rowCnt = " + rowCnt);
        return rowCnt;
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public int write(CommentDto commentDto) throws Exception {
        boardDao.updateCommentCnt(commentDto.getBno(), 1);
//                throw new Exception("test");
        return commentDao.insert(commentDto);
    }

    @Override
    public List<CommentDto> getList(Integer bno) throws Exception {
//        throw new Exception("test");
        return commentDao.selectAll(bno);
    }

    @Override
    public CommentDto read(Integer cno) throws Exception {
        return commentDao.select(cno);
    }

    @Override
    public int modify(CommentDto commentDto) throws Exception {
        return commentDao.update(commentDto);
    }
}

 

[CommentService]

package com.fastcampus.ch4.service;

import com.fastcampus.ch4.domain.CommentDto;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

public interface CommentService {
    int getCount(Integer bno) throws Exception;

    @Transactional(rollbackFor = Exception.class)
    int remove(Integer cno, Integer bno, String commenter) throws Exception;

    @Transactional(rollbackFor = Exception.class)
    int write(CommentDto commentDto) throws Exception;

    List<CommentDto> getList(Integer bno) throws Exception;

    CommentDto read(Integer cno) throws Exception;

    int modify(CommentDto commentDto) throws Exception;
}

[CommentSeriviceImplTest]

package com.fastcampus.ch4.service;

import com.fastcampus.ch4.dao.*;
import com.fastcampus.ch4.domain.*;
import org.junit.*;
import org.junit.runner.*;
import org.springframework.beans.factory.annotation.*;
import org.springframework.test.context.*;
import org.springframework.test.context.junit4.*;

import java.util.*;

import static org.junit.Assert.*;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"file:src/main/webapp/WEB-INF/spring/root-context.xml"})
public class CommentServiceImplTest {
    @Autowired
    CommentService commentService;
    @Autowired
    CommentDao commentDao;
    @Autowired
    BoardDao boardDao;

    @Test
    public void remove() throws Exception {
        boardDao.deleteAll();

        BoardDto boardDto = new BoardDto("hello", "hello", "asdf");
        assertTrue(boardDao.insert(boardDto) == 1);
        Integer bno = boardDao.selectAll().get(0).getBno();
        System.out.println("bno = " + bno);

        commentDao.deleteAll(bno);
        CommentDto commentDto = new CommentDto(bno,0,"hi","qwer");

        assertTrue(boardDao.select(bno).getComment_cnt() == 0);
        assertTrue(commentService.write(commentDto)==1);
        assertTrue(boardDao.select(bno).getComment_cnt() == 1);

        Integer cno = commentDao.selectAll(bno).get(0).getCno();

        // 일부러 예외를 발생시키고 Tx가 취소되는지 확인해야.
        int rowCnt = commentService.remove(cno, bno, commentDto.getCommenter());
        assertTrue(rowCnt==1);
        assertTrue(boardDao.select(bno).getComment_cnt() == 0);
    }

    @Test
    public void write() throws  Exception {
        boardDao.deleteAll();

        BoardDto boardDto = new BoardDto("hello", "hello", "asdf");
        assertTrue(boardDao.insert(boardDto) == 1);
        Integer bno = boardDao.selectAll().get(0).getBno();
        System.out.println("bno = " + bno);

        commentDao.deleteAll(bno);
        CommentDto commentDto = new CommentDto(bno,0,"hi","qwer");

        assertTrue(boardDao.select(bno).getComment_cnt() == 0);
        assertTrue(commentService.write(commentDto)==1);

        Integer cno = commentDao.selectAll(bno).get(0).getCno();
        assertTrue(boardDao.select(bno).getComment_cnt() == 1);
    }
}