19.05.11 JSP 게시판 - 글삭제 구현 (동영상 51강)

Back-End/JSP 2019. 5. 11. 16:32
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글삭제

BoardDeleteForm.jsp

     ↓

글삭제 처리

BoardDeleteProc.jsp

     ↓

글삭제

BoardDAO.java

     ↓

 게시글보기

BoardList.jsp

 

3개 페이지만 바뀌고 나머지 페이지는 동일함

 

 

 

BoardDeleteForm.jsp (게시글 삭제)

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<%@page import="model.BoardDAO"%>
<%@page import="model.BoardBean"%>
<%@ page language="java" contentType="text/html; charset=EUC-KR"
    pageEncoding="EUC-KR"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<body>
 
    <%
        BoardDAO bdao = new BoardDAO();
        //String 형식이기 때문에 포장클래스를 사용해서 타입을 변환한다.
        int num = Integer.parseInt(request.getParameter("num"));
 
        //하나의 게시글을 리턴해야하기 때문에 (getOneUpdateBoard메소드를 사용해도 된다.)
        BoardBean bean = bdao.getOneUpdateBoard(num);
    %>
    <center>
        <h2>게시글 삭제</h2>
        <!-- 패스워드 값을 넘기기때문에 post방식 사용 -->
        <form action="BoardDeleteProc.jsp" method="post">
            <table width="600" border="1" bgcolor="skyblue">
                <tr height="40">
                    <td width="120" align="center">작성자</td>
                    <td width="180" align="center"><%=bean.getWriter()%></td>
 
                    <td width="120" align="center">작성일</td>
                    <td width="180" align="center"><%=bean.getReg_date()%></td>
                </tr>
 
                <tr height="40">
                    <td width="120" align="center">제목</td>
                    <td align="center" colspan="3"><%=bean.getSubject()%></td>
                </tr>
 
                <tr height="40">
                    <td width="120" align="center">패스워드</td>
                    <!-- 패스워드는 직접받아야되기때문에 빈에서 받지않는다.-->
                    <td align="Left" colspan="3"><input type="password"
                        name="password" size="60"></td>
                </tr>
 
 
                <tr height="40">
                    <td align="center" colspan="4"><input type="hidden" name="num"
                        value="<%=num%>">
                    <!-- 처리파일에 num값을 그대로 넘겨준다 (삭제하기 위해서) --> <input type="submit"
                        value="글삭제"> &nbsp;&nbsp; <input type="button"
                        onclick="location.href='BoardList.jsp'" value="목록보기"></td>
                </tr>
 
 
            </table>
        </form>
    </center>
</body>
</html>
cs

 

 

BoardDeleteProc.jsp (게시글 삭제 처리)

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<%@page import="model.BoardDAO"%>
<%@ page language="java" contentType="text/html; charset=EUC-KR"
    pageEncoding="EUC-KR"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<body>
    <!-- 패스워드랑 num만 받기 때문에 한글깨짐 방지는 따로 안해도된다. -->
 
    <%
        //두가지의 값만 받기때문에 유즈빈을 사용해도 되지만, request를 사용했다. (패스워드와 넘버를 받는다.)
        String pass = request.getParameter("password");
        int num = Integer.parseInt(request.getParameter("num"));
 
        //데이터베이스 연결
        BoardDAO bdao = new BoardDAO();
        String password = bdao.getPass(num);
 
        //기존 패스워드값과 delete form에서 작성한 패스워드를 비교
        if (pass.equals(password)) {
            //패스워드가 둘다 같다면
            bdao.deleteBoard(num);
 
            //응답한다음 BoardList.jsp로 이동함
            response.sendRedirect("BoardList.jsp");
 
        } else {
    %>
    <script>
        //패스워드가 틀리면 바로 전페이지로 돌아가게끔 script 코드 작성
        alert("패스워드가 틀려서 삭제 할수 없습니다. 패스워드를 확인해주세요.");
        history.go(-1);
    </script>
    <%
        }
    %>
</body>
</html>
cs

 

 

BoardDAO.java (DB연결)

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package model;
 
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.Vector;
 
import javax.naming.InitialContext;
import javax.sql.DataSource;
import javax.naming.Context;
 
public class BoardDAO {
 
    // 데이터베이스에 연결하기 위한 설정
    Connection con;
    PreparedStatement pstmt;
    ResultSet rs;
 
    // 데이터베이스의 커넥션들을 사용하도록 설정하는 메소드
    public void getCon() {
 
        try { // 데이터베이스에 접속할때는 예외처리를 해주어야한다.
 
            Context initctx = new InitialContext(); // 외부에서 데이터를 읽어들어야 하기 때문에 Context 객체 생성
            // 톰캣 서버에 정보를 담아놓은 곳으로 이동함
            Context envctx = (Context) initctx.lookup("java:comp/env"); // lookup메소드를 이용해서 자료를 읽어오는 코드
            DataSource ds = (DataSource) envctx.lookup("jdbc/pool"); // datasource 객체를 선언 , 오브젝트 타입이기 때문에 타입변환을 한다.
 
            con = ds.getConnection(); // 데이터 소스를 기준으로 커넥션을 연결함
        } catch (Exception e) {
            e.printStackTrace(); // 어느부분이 잘못되었는지 알려주는 예외처리
        }
    }
 
    // 하나의 새로운 게시글이 넘어와서 저장되는 메소드
    public void insertBoard(BoardBean bean) {
        getCon();
        // 빈클래스에 넘어오지 않았던 데이터들을 초기화 해주어야 한다.
 
        int ref = 0// 글그룹을 의미한다, 쿼리를 실행시켜서 가장 큰 ref값을 가져온후 +1을 더해주면 된다.
        int re_step = 1// 새글이고, 부모글은 글 스텝(Re_step), 글 레벨(Re_level)은 1이기 때문에 초기값을 1을 준다.
        int re_level = 1// 새글이고, 부모글은 글 스텝(Re_step), 글 레벨(Re_level)은 1이기 때문에 초기값을 1을 준다.
 
        try {
 
            // 가장큰 ref값을 읽어오는 쿼리 준비함 (새로운 글은 ref가 가장크기 때문)
            String refsql = "select max(ref) from board"// board테이블로부터 가장큰 ref를 검색
            // 쿼리를 실행할 객체
            pstmt = con.prepareStatement(refsql);
            // 쿼리 실행후 결과를 리턴
            rs = pstmt.executeQuery();
            if (rs.next()) { // 쿼리(rs)가 결과값이 있다면 실행하는 구문
                ref = rs.getInt(1+ 1// 최대값에 1을 더해서 글그룹을 설정. 새로운글은 ref숫자가 하나씩 올라가야 하기 때문
            }
 
            // 실제로 게시글 전체값을 테이블에 저장
            String sql = "insert into board values(board_seq.NEXTVAL,?,?,?,?,sysdate,?,?,?,0,?)"// 첫번째 값은 ?가 아니라 시퀀스를
                                                                                                    // 사용해
                                                                                                    // 시퀀스에 이미 들어가있는값의
                                                                                                    // 다음값을 자동으로 매핑해서
                                                                                                    // 넣어준다.
            pstmt = con.prepareStatement(sql);
            // ?에 값을 매핑한다. //0은 카운트값이기때문 0을 넣어주었다
            pstmt.setString(1, bean.getWriter());
            pstmt.setString(2, bean.getEmail());
            pstmt.setString(3, bean.getSubject());
            pstmt.setString(4, bean.getPassword());
            pstmt.setInt(5, ref);
            pstmt.setInt(6, re_step);
            pstmt.setInt(7, re_level);
            pstmt.setString(8, bean.getContent());
 
            // 쿼리를 실행하시오.
            pstmt.executeUpdate();
            // 자원 반납
            con.close();
 
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
    // 모든 게시글을 리턴해주는 메소드 작성
    public Vector<BoardBean> getAllBoard() {
        // 리턴할 객체 선언
        Vector<BoardBean> v = new Vector<>();
 
        getCon();
 
        try {
            // 쿼리 준비
            String sql = "select * from board order by ref desc, re_step asc "// 게시판 글을 내림차순으로 정렬하기 위한 sql코드
            // 쿼리를 실행할 객체 선언
            pstmt = con.prepareStatement(sql);
            // 쿼리 실행후 결과 저장
            rs = pstmt.executeQuery();
            // 데이터 개수가 몇개인지 모르기에 반복문을 이용하여 데이터를 추출
            while (rs.next()) {
                // 데이터를 패키징 시키기(가방 = Boardbean 클래스를 이용) 패키지 안에 넣는다는 의미
                BoardBean bean = new BoardBean();
                bean.setNum(rs.getInt(1));
                bean.setWriter(rs.getString(2));
                bean.setEmail(rs.getString(3));
                bean.setSubject(rs.getString(4));
                bean.setPassword(rs.getString(5));
                bean.setReg_date(rs.getDate(6).toString()); // reg데이터가 String타입으로 변한다.
                bean.setRef(rs.getInt(7));
                bean.setRe_step(rs.getInt(8));
                bean.setRe_level(rs.getInt(9));
 
                bean.setReadcount(rs.getInt(10));
                bean.setContent(rs.getString(11));
                // 패키징한 데이터를 벡터에 저장
                v.add(bean);
            }
 
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
 
        return v;
    }
 
    // BoardInfo를 사용할 때 하나의 게시글을 리턴하는 메소드
    public BoardBean getOneBoard(int num) {
        // 리턴타입 선언(객체 생성)
        BoardBean bean = new BoardBean();
        getCon();
        try {
 
            // 조회수 증가 쿼리
            String readsql = "update board set readcount = readcount+1 where num=?"// 읽은 게시글의 조회수를 늘리기 위한 sql문
            pstmt = con.prepareStatement(readsql);
            pstmt.setInt(1, num);
            pstmt.execute();
 
            // 쿼리 준비
            String sql = "select * from board where num=?";
            // 쿼리 실행 객체
            pstmt = con.prepareStatement(sql);
            pstmt.setInt(1, num);
            // 쿼리 실행후 결과를 리턴
            rs = pstmt.executeQuery();
 
            if (rs.next()) { // 게시글에대한 모든 정보를 하나씩 가져옴
                bean.setNum(rs.getInt(1));
                bean.setWriter(rs.getString(2));
                bean.setEmail(rs.getString(3));
                bean.setSubject(rs.getString(4));
                bean.setPassword(rs.getString(5));
                bean.setReg_date(rs.getDate(6).toString()); // reg데이터가 String타입으로 변한다.
                bean.setRef(rs.getInt(7));
                bean.setRe_step(rs.getInt(8));
                bean.setRe_level(rs.getInt(9));
                bean.setReadcount(rs.getInt(10));
                bean.setContent(rs.getString(11));
 
            }
 
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
 
        return bean;
    }
 
    // 답변글이 저장되는 메소드
    public void reWriteBoard(BoardBean bean) {// re_step와 re_level을 먼저 수정해야 한다.
                                                // 답변글은 부모글의 step와 level보다 1씩 증가하기 때문이다.
                                                // 부모글그룹과 글레벨 글스텝을 읽어들인다.
        int ref = bean.getRef();
        int re_step = bean.getRe_step();
        int re_level = bean.getRe_level();
 
        getCon();
 
        try {
            ///////////////////// 핵심코드///////////////////////////
            // 부모글보다 큰 re_level의 값을 전부 1씩 증가시켜줌(같은 레벨에 있는 것들만)
            String levelsql = "update board set re_level=re_level+1 where ref=? and re_level > ?";
            // 코드해석 = board 테이블에 있는 re_level을 1씩 증가시켜라 (단, ref가 같고 re_level보다 작은것만)
            pstmt = con.prepareStatement(levelsql);
            // 쿼리 실행 객체 선언
            pstmt.setInt(1, ref);
            pstmt.setInt(2, re_level);
            // 쿼리 실행
            pstmt.executeUpdate();
            // 답변글 데이터를 저장
            String sql = "insert into board values(board_seq.NEXTVAL,?,?,?,?,sysdate,?,?,?,0,?)";
            // 첫번째 값은 ?가 아니라 시퀀스를 사용해
            // 시퀀스에 이미 들어가있는값의
            // 다음값을 자동으로 매핑해서
            // 넣어준다.
 
            pstmt = con.prepareStatement(sql);
            // ?에 값을 매핑한다
            pstmt.setString(1, bean.getWriter());
            pstmt.setString(2, bean.getEmail());
            pstmt.setString(3, bean.getSubject());
            pstmt.setString(4, bean.getPassword());
            pstmt.setInt(5, ref); // 부모의 ref값을 넣어줌
            pstmt.setInt(6, re_step + 1); // 답글이기 때문에 부모글 re_step에 1을 더해준다.
            pstmt.setInt(7, re_level + 1); // 답글이기 때문에 부모글 re_level에 1을 더해준다.
            pstmt.setString(8, bean.getContent());
            pstmt.executeUpdate(); //
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
 
    }
 
    // boardupdate용 Delete시 하나의 게시글을 리턴
 
    public BoardBean getOneUpdateBoard(int num) {
        // 리턴타입 선언(객체 생성)
        BoardBean bean = new BoardBean();
        getCon();
        try {
 
            // 쿼리 준비
            String sql = "select * from board where num=?";
            // 쿼리 실행 객체
            pstmt = con.prepareStatement(sql);
            pstmt.setInt(1, num);
            // 쿼리 실행후 결과를 리턴
            rs = pstmt.executeQuery();
 
            if (rs.next()) { // 게시글에대한 모든 정보를 하나씩 가져옴
                bean.setNum(rs.getInt(1));
                bean.setWriter(rs.getString(2));
                bean.setEmail(rs.getString(3));
                bean.setSubject(rs.getString(4));
                bean.setPassword(rs.getString(5));
                bean.setReg_date(rs.getDate(6).toString()); // reg데이터가 String타입으로 변한다.
                bean.setRef(rs.getInt(7));
                bean.setRe_step(rs.getInt(8));
                bean.setRe_level(rs.getInt(9));
                bean.setReadcount(rs.getInt(10));
                bean.setContent(rs.getString(11));
 
            }
 
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
 
        return bean;
    }
 
    // update 와 delete 시 필요한 패스워드값을 리턴해주는 메소드
    public String getPass(int num) {// 리턴할 변수 객체 선언
        String pass = "";
        // DB연결
        getCon();
 
        try {
 
            // 쿼리 준비
            String sql = "select password from board where num=?";
            // 쿼리 실행할 객체 선언
            pstmt = con.prepareStatement(sql);
            pstmt.setInt(1, num);
            rs = pstmt.executeQuery();
            // 패스워드 값을 저장
            if (rs.next()) {
                pass = rs.getString(1);
            }
            // 자원 반납
            con.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
 
        return pass;
 
    }
 
    // 하나의 게시글을 수정하는 메소드
    public void updateBoard(BoardBean bean) {
        getCon();
 
        try {
            // 쿼리 준비
            String sql = "update board set subject=? , content=? where num=?";
            pstmt = con.prepareStatement(sql);
 
            // ?값을 대입
            pstmt.setString(1, bean.getSubject());
            pstmt.setString(2, bean.getContent());
            pstmt.setInt(3, bean.getNum());
 
            pstmt.executeUpdate();
 
            con.close();// 자원반납
 
        } catch (Exception e) {
            e.printStackTrace();
        }
 
    }
 
    // 하나의 게시글을 삭제 하는 메소드
    public void deleteBoard(int num) {
        getCon();
        try {
            // 쿼리 준비
            String sql = "delete from board where num=?";
            pstmt = con.prepareStatement(sql);
 
            // 쿼리 실행을 위한 인덱스와 값을 넣어주기
            pstmt.setInt(1, num);
 
            // 쿼리 실행
            pstmt.executeUpdate();
 
            // 자원 반납
            con.close();
 
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
}
 
cs

 

 

 

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