🐣 게시판 목록 화면 및 페이징-TDD

⚫ 게시물 목록 페이징

⚫ LIMIT [offset], row_count

✅ offset : 대상이 처음에서부터 떨어져있는 정도
✅ row_count : 읽어올 행(row)의 수

⚫ 실습

📃 PageHandler.java

package com.fastcampus.ch4.domain;

public class PageHandler  {
    private int totalCnt; // 총 게시물 게수
    private int pageSize; // 한 페이지의 크기
    private int naviSize = 10; // 페이지 내비게이션의 크기
    private int totalPage; // 전체 페이지의 개수
    private int page; // 현제 페이지
    private int beginPage; // 내비게이션의 첫번째 페이지
    private int endPage; // 내비게이션의 마지막 페이지
    // 이전 페이지로 이동하는 링크를 보여줄 것인지 여부. endPage==totalPage이면, showNext는 false
    private boolean showPrev;
    // 다음 페이지로 이동하는 링크를 보여줄 것인지 여부, beginPage==1이 아니면 showPrev는 false
    private boolean showNext;

    public PageHandler(int totalCnt, int page){
        this(totalCnt,page, 10);
    }
    public PageHandler(int totalCnt, int page, int pageSize){
        this.totalCnt = totalCnt;
        this.page = page;
        this.pageSize = pageSize;
        
		// 올림/내림/반올림: Math.ceil / Math.floor / Math.round
        totalPage = (int)Math.ceil(totalCnt / (double)pageSize);
        
		totalPage = (int)Math.ceil(totalCnt / (double)pageSize); // Math.ceil 올림
        beginPage = (page-1) / naviSize * naviSize + 1;
        endPage = Math.min(beginPage + naviSize - 1, totalPage);
        showPrev = beginPage != 1;
        showNext = endPage != totalPage;
    }

    void print() {
        System.out.println("page = "+ page);
        System.out.print(showPrev? "[PREV] " : "");

        for(int i=beginPage;i<=endPage;i++) {
            System.out.print(i+" ");
        }
        System.out.println(showNext? " [NEXT]" : "");
    }

    @Override
    public String toString() { 생략 }

⭕ PageHandlerTest

package com.fastcampus.ch4.domain;

import org.junit.Test;
import static org.junit.Assert.*;

public class PageHandlerTest {
    @Test
    public void test(){
        // page=1, beginPage=1, endpage=10, showPrev=false, showNext=true
        PageHandler ph = new PageHandler(250,1);
        ph.print();
        System.out.println("ph = " + ph);
        assertTrue(ph.getBeginPage() ==1);
        assertTrue(ph.getEndPage() ==10);
    }

    @Test
    public void test2(){
        // page=11, beginPage=11, endpage=20, showPrev=true, showNext=true
        PageHandler ph = new PageHandler(250,11);
        ph.print();
        System.out.println("ph = " + ph);
        assertTrue(ph.getBeginPage()==11);
        assertTrue(ph.getEndPage()==20);
    }

    @Test
    public void test3(){
        // page=25, beginPage=21, endpage=26, showPrev=true, showNext=false
        PageHandler ph = new PageHandler(255,25);
        ph.print();
        System.out.println("ph = " + ph);
        assertTrue(ph.getBeginPage()==21);
        assertTrue(ph.getEndPage()==26);
    }

}

---

📃 boardMapper.xml   |   BoardDaoImpl.java

✔️ BoardDaoImpl - refactor - Extract Interface

⭕ BoardDaoImplTest

✔️ BoardDaoImpl - Go to - Test

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

	@Test
    public void insertTestData() throws Exception{
        boardDao.deleteAll();
        for (int i=1; i<=220; i++){
            BoardDto boardDto = new BoardDto("title"+i,"no content", "asdf");
            boardDao.insert(boardDto);
        }
    }
    
    @Test
    public void countTest() throws Exception {
        boardDao.deleteAll();
        assertTrue(boardDao.count()==0);

        BoardDto boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);
        assertTrue(boardDao.count()==1);

        assertTrue(boardDao.insert(boardDto)==1);
        assertTrue(boardDao.count()==2);
    }

    @Test
    public void deleteAllTest() throws Exception {
        boardDao.deleteAll();
        assertTrue(boardDao.count()==0);

        BoardDto boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);
        assertTrue(boardDao.deleteAll()==1);
        assertTrue(boardDao.count()==0);

        boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);
        assertTrue(boardDao.insert(boardDto)==1);
        assertTrue(boardDao.deleteAll()==2);
        assertTrue(boardDao.count()==0);
    }

    @Test
    public void deleteTest() throws Exception {
        boardDao.deleteAll();
        assertTrue(boardDao.count()==0);

        BoardDto boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);
        Integer bno = boardDao.selectAll().get(0).getBno();
        assertTrue(boardDao.delete(bno, boardDto.getWriter())==1);
        assertTrue(boardDao.count()==0);

        assertTrue(boardDao.insert(boardDto)==1);
        bno = boardDao.selectAll().get(0).getBno();
        assertTrue(boardDao.delete(bno, boardDto.getWriter()+"222")==0);
        assertTrue(boardDao.count()==1);

        assertTrue(boardDao.delete(bno, boardDto.getWriter())==1);
        assertTrue(boardDao.count()==0);

        assertTrue(boardDao.insert(boardDto)==1);
        bno = boardDao.selectAll().get(0).getBno();
        assertTrue(boardDao.delete(bno+1, boardDto.getWriter())==0);
        assertTrue(boardDao.count()==1);
    }

    @Test
    public void insertTest() throws Exception {
        boardDao.deleteAll();
        BoardDto boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);

        boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);
        assertTrue(boardDao.count()==2);

        boardDao.deleteAll();
        boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);
        assertTrue(boardDao.count()==1);
    }

    @Test
    public void selectAllTest() throws Exception {
        boardDao.deleteAll();
        assertTrue(boardDao.count()==0);

        List<BoardDto> list = boardDao.selectAll();
        assertTrue(list.size() == 0);

        BoardDto boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);

        list = boardDao.selectAll();
        assertTrue(list.size() == 1);

        assertTrue(boardDao.insert(boardDto)==1);
        list = boardDao.selectAll();
        assertTrue(list.size() == 2);
    }

    @Test
    public void selectTest() throws Exception {
        boardDao.deleteAll();
        assertTrue(boardDao.count()==0);

        BoardDto boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);

        Integer bno = boardDao.selectAll().get(0).getBno();
        boardDto.setBno(bno);
        BoardDto boardDto2 = boardDao.select(bno);
        assertTrue(boardDto.equals(boardDto2));
    }

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

        for (int i = 1; i <= 10; i++) {
            BoardDto boardDto = new BoardDto(""+i, "no content"+i, "asdf");
            boardDao.insert(boardDto);
        }

        Map map = new HashMap();
        map.put("offset", 0);
        map.put("pageSize", 3);

        List<BoardDto> list = boardDao.selectPage(map);
        assertTrue(list.get(0).getTitle().equals("10"));
        assertTrue(list.get(1).getTitle().equals("9"));
        assertTrue(list.get(2).getTitle().equals("8"));

        map = new HashMap();
        map.put("offset", 0);
        map.put("pageSize", 1);

        list = boardDao.selectPage(map);
        assertTrue(list.get(0).getTitle().equals("10"));

        map = new HashMap();
        map.put("offset", 7);
        map.put("pageSize", 3);

        list = boardDao.selectPage(map);
        assertTrue(list.get(0).getTitle().equals("3"));
        assertTrue(list.get(1).getTitle().equals("2"));
        assertTrue(list.get(2).getTitle().equals("1"));
    }

    @Test
    public void updateTest() throws Exception {
        boardDao.deleteAll();
        BoardDto boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);

        Integer bno = boardDao.selectAll().get(0).getBno();
        System.out.println("bno = " + bno);
        boardDto.setBno(bno);
        boardDto.setTitle("yes title");
        assertTrue(boardDao.update(boardDto)==1);

        BoardDto boardDto2 = boardDao.select(bno);
        assertTrue(boardDto.equals(boardDto2));
    }

    @Test
    public void increaseViewCntTest() throws Exception {
        boardDao.deleteAll();
        assertTrue(boardDao.count()==0);

        BoardDto boardDto = new BoardDto("no title", "no content", "asdf");
        assertTrue(boardDao.insert(boardDto)==1);
        assertTrue(boardDao.count()==1);

        Integer bno = boardDao.selectAll().get(0).getBno();
        assertTrue(boardDao.increaseViewCnt(bno)==1);

        boardDto = boardDao.select(bno);
        assertTrue(boardDto!=null);
        assertTrue(boardDto.getView_cnt() == 1);

        assertTrue(boardDao.increaseViewCnt(bno)==1);
        boardDto = boardDao.select(bno);
        assertTrue(boardDto!=null);
        assertTrue(boardDto.getView_cnt() == 2);
    }
}

---

📃 BoardServieImpl.java

✔️ BoardDaoImpl - refactor - Extract Interface

package com.fastcampus.ch4.service;

@Service
public class BoardServiceImpl implements BoardService {
    @Autowired
    BoardDao boardDao;

    @Override
    public int getCount() throws Exception {
        return boardDao.count();
    }

    @Override
    public int remove(Integer bno, String writer) throws Exception {
        return boardDao.delete(bno, writer);
    }

    @Override
    public int write(BoardDto boardDto) throws Exception {
        return boardDao.insert(boardDto);
    }

    @Override
    public List<BoardDto> getList() throws Exception {
        return boardDao.selectAll();
    }

    @Override
    public BoardDto read(Integer bno) throws Exception {
        BoardDto boardDto = boardDao.select(bno);
        boardDao.increaseViewCnt(bno);

        return boardDto;
    }

    @Override
    public List<BoardDto> getPage(Map map) throws Exception {
        return boardDao.selectPage(map);
    }

    @Override
    public int modify(BoardDto boardDto) throws Exception {
        return boardDao.update(boardDto);
    }
}

---

📃 BoardController.java

@Controller
@RequestMapping("/board")
public class BoardController {
    @Autowired
    BoardService boardService;

    @GetMapping("/list")
    public String list(Integer page, Integer pageSize, Model m, HttpServletRequest request) {
        if(!loginCheck(request))
            return "redirect:/login/login?toURL="+request.getRequestURL();

        if(page==null) page=1;
        if(pageSize==null) pageSize=10;

        try {
            int totalCnt = boardService.getCount();
            PageHandler pageHandler = new PageHandler(totalCnt, page, pageSize);
            Map map = new HashMap<>();
            map.put("offset", (page-1)*pageSize);
            map.put("pageSize", pageSize);

            List<BoardDto> list = boardService.getPage(map);
            m.addAttribute("list", list);
            m.addAttribute("ph", pageHandler);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return "boardList"; // 로그인을 한 상태이면, 게시판 화면으로 이동

    private boolean loginCheck(HttpServletRequest request) {
        HttpSession session = request.getSession();
        return session.getAttribute("id")!=null;
    }
}

---

🧱 boardList.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta http-equiv="x-ua-compatible" content="IE-edge">
    <meta name="viewport" content="width-device-width, initial-scal-1.0">
    <meta charset="UTF-8">
    <title>fastcampus</title>
    <link rel="stylesheet" href="<c:url value='/css/menu.css'/>">

</head>
<body>
<div id="menu">
    <ul>
        <li id="logo">fastcampus</li>
        <li><a href="<c:url value='/'/>">Home</a></li>
        <li><a href="<c:url value='/board/list'/>">Board</a></li>
        <li><a href="<c:url value='/login/login'/>">login</a></li>
        <li><a href="<c:url value='/register/add'/>">Sign in</a></li>
        <li><a href=""><i class="fas fa-search small"></i></a></li>
    </ul>
</div><div style="text-align:center">
    <table border="1">
        <tr>
            <th class="no">번호</th>
            <th class="title">제목</th>
            <th class="writer">이름</th>
            <th class="reg_date">등록일</th>
            <th class="view_cnt">조회수</th>
        </tr>
        <c:forEach var="board" items="${list}">
        <tr>
            <td>${board.bno}</td>
            <td>${board.title}</td>
            <td>${board.writer}</td>
            <td>${board.reg_date}</td>
            <td>${board.view_cnt}</td>
        </tr>
        </c:forEach>
    </table>
    <br>
    <div>
        <c:if test="${ph.showPrev}">
            <a href="<c:url value='/board/list?page=${ph.beginPage-1}&pageSize=${ph.pageSize}'/>">&lt;</a>
        </c:if>
        <c:forEach var="i" begin="${ph.beginPage}" end="${ph.endPage}">
            <a href="<c:url value='/board/list?page=${i}&pageSize=${ph.pageSize}'/>">${i}</a>
        </c:forEach>
        <c:if test="${ph.showNext}">
            <a href="<c:url value='/board/list?page=${ph.endPage+1}&pageSize=${ph.pageSize}'/>">&gt;</a>
        </c:if>
    </div>
</div>
</body>
</html>

---

참고) 자바의 정석 | 남궁성과 끝까지 간다