JSP & Servlet 게시판 구현하기(게시글 내용 조회)

지난번에 게시글 목록 조회 기능을 구현 하였다.

https://nullgoyatten.tistory.com/25

JSP & Servlet 게시판 구현하기(게시글 목록 조회)

 

이번엔 작성된 내용 조회를 구현해 보도록 하자

 

1. ArticleDao 에 게시글 조회 관련 기능 추가 추가 (특정번호에 해당하는 게시글 데이터 읽기, 조회수 증가 하기)

경로 : article.dao> ArticleDao.java

public Article selectById(Connection conn, int no) throws SQLException {
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		try {
			pstmt = conn.prepareStatement(
					"select * from article where article_no = ?");
			pstmt.setInt(1, no);
			rs = pstmt.executeQuery();
			Article article = null;
			if (rs.next()) {
				article = convertArticle(rs);
			}
			return article;
		} finally {
			JdbcUtil.close(rs);
			JdbcUtil.close(pstmt);
		}
	}
	
	public void increaseReadCount(Connection conn, int no) throws SQLException {
		try (PreparedStatement pstmt = 
				conn.prepareStatement(
						"update article set read_cnt = read_cnt + 1 "+
						"where article_no = ?")) {
			pstmt.setInt(1, no);
			pstmt.executeUpdate();
		}
	}

1-1. ArticleDao의 전체 코드

package article.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import article.model.Article;
import article.model.Writer;
import jdbc.JdbcUtil;

public class ArticleDao {

	public Article insert(Connection conn, Article article) throws SQLException {
		PreparedStatement pstmt = null;
		Statement stmt = null;
		ResultSet rs = null;
		try {
			pstmt = conn.prepareStatement("insert into article "
					+ "(writer_id, writer_name, title, regdate, moddate, read_cnt) "
					+ "values (?,?,?,?,?,0)");
			pstmt.setString(1, article.getWriter().getId());
			pstmt.setString(2, article.getWriter().getName());
			pstmt.setString(3, article.getTitle());
			pstmt.setTimestamp(4, toTimestamp(article.getRegDate()));
			pstmt.setTimestamp(5, toTimestamp(article.getModifiedDate()));
			int insertedCount = pstmt.executeUpdate();

			if (insertedCount > 0) {
				stmt = conn.createStatement();
				rs = stmt.executeQuery("select last_insert_id() from article");
				if (rs.next()) {
					Integer newNo = rs.getInt(1);
					return new Article(newNo,
							article.getWriter(),
							article.getTitle(),
							article.getRegDate(),
							article.getModifiedDate(),
							0);
				}
			}
			return null;
		} finally {
			JdbcUtil.close(rs);
			JdbcUtil.close(stmt);
			JdbcUtil.close(pstmt);
		}
	}

	private Timestamp toTimestamp(Date date) {
		return new Timestamp(date.getTime());
	}
	
	public int selectCount(Connection conn) throws SQLException {
		Statement stmt = null;
		ResultSet rs = null;
		try {
			stmt = conn.createStatement();
			rs = stmt.executeQuery("select count(*) from article");
			if (rs.next()) {
				return rs.getInt(1);
			}
			return 0;
		} finally {
			JdbcUtil.close(rs);
			JdbcUtil.close(stmt);
		}
	}
	
	public List<Article> select(Connection conn, int startRow, int size) throws SQLException {
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		try {
			pstmt = conn.prepareStatement("select * from article " +
					"order by article_no desc limit ?, ?");
			pstmt.setInt(1, startRow);
			pstmt.setInt(2, size);
			rs = pstmt.executeQuery();
			List<Article> result = new ArrayList<>();
			while (rs.next()) {
				result.add(convertArticle(rs));
			}
			return result;
		} finally {
			JdbcUtil.close(rs);
			JdbcUtil.close(pstmt);
		}
	}

	private Article convertArticle(ResultSet rs) throws SQLException {
		return new Article(rs.getInt("article_no"),
				new Writer(
						rs.getString("writer_id"),
						rs.getString("writer_name")),
				rs.getString("title"),
				toDate(rs.getTimestamp("regdate")),
				toDate(rs.getTimestamp("moddate")),
				rs.getInt("read_cnt"));
	}

	private Date toDate(Timestamp timestamp) {
		return new Date(timestamp.getTime());
	}
	
	public Article selectById(Connection conn, int no) throws SQLException {
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		try {
			pstmt = conn.prepareStatement(
					"select * from article where article_no = ?");
			pstmt.setInt(1, no);
			rs = pstmt.executeQuery();
			Article article = null;
			if (rs.next()) {
				article = convertArticle(rs);
			}
			return article;
		} finally {
			JdbcUtil.close(rs);
			JdbcUtil.close(pstmt);
		}
	}
	
	public void increaseReadCount(Connection conn, int no) throws SQLException {
		try (PreparedStatement pstmt = 
				conn.prepareStatement(
						"update article set read_cnt = read_cnt + 1 "+
						"where article_no = ?")) {
			pstmt.setInt(1, no);
			pstmt.executeUpdate();
		}
	}
}

 

2. ArticleContentDao 에 게시글 조회 관련 기능 추가 추가 (특정번호에 해당하는 게시글 내용 읽기)

경로 : article.dao> ArticleContentDao.java

public ArticleContent selectById(Connection conn, int no) throws SQLException {
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		try {
			pstmt = conn.prepareStatement(
					"select * from article_content where article_no = ?");
			pstmt.setInt(1, no);
			rs = pstmt.executeQuery();
			ArticleContent content = null;
			if (rs.next()) {
				content = new ArticleContent(
						rs.getInt("article_no"), rs.getString("content"));
			}
			return content;
		} finally {
			JdbcUtil.close(rs);
			JdbcUtil.close(pstmt);
		}
	}

2-1. ArticleContentDao의 전체 코드

package article.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import article.model.ArticleContent;
import jdbc.JdbcUtil;

public class ArticleContentDao {

	public ArticleContent insert(Connection conn, ArticleContent content) 
	throws SQLException {
		PreparedStatement pstmt = null;
		try {
			pstmt = conn.prepareStatement(
					"insert into article_content " + 
					"(article_no, content) values (?,?)");
			pstmt.setLong(1, content.getNumber());
			pstmt.setString(2, content.getContent());
			int insertedCount = pstmt.executeUpdate();
			if (insertedCount > 0) {
				return content;
			} else {
				return null;
			}
		} finally {
			JdbcUtil.close(pstmt);
		}
	}
	
	public ArticleContent selectById(Connection conn, int no) throws SQLException {
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		try {
			pstmt = conn.prepareStatement(
					"select * from article_content where article_no = ?");
			pstmt.setInt(1, no);
			rs = pstmt.executeQuery();
			ArticleContent content = null;
			if (rs.next()) {
				content = new ArticleContent(
						rs.getInt("article_no"), rs.getString("content"));
			}
			return content;
		} finally {
			JdbcUtil.close(rs);
			JdbcUtil.close(pstmt);
		}
	}
}

 

3. ArticleData 작성(ReadArticleService 클래스에 구현할 getArticle()메서드의 리턴 타입으로 Article객체와 ArticleContent객체를 한 객체에 담기 위한 용도)

경로 : article.service > ArticleData.java

package article.service;

import article.model.Article;
import article.model.ArticleContent;

public class ArticleData {

	private Article article;
	private ArticleContent content;

	public ArticleData(Article article, ArticleContent content) {
		this.article = article;
		this.content = content;
	}

	public Article getArticle() {
		return article;
	}

	public String getContent() {
		return content.getContent();
	}

}

 

4. ArticleNotFoundException 작성(article테이블에 데이터가 존재하지 않을때 발생)

경로 : article.service > ArticleNotFoundException.java

package article.service;

public class ArticleNotFoundException extends RuntimeException {

}

 

5. ArticleContentNotFoundException 작성(article테이블에 데이터가 존재하지 않을때 발생)

경로 : article.service > ArticleContentNotFoundException.java

package article.service;

public class ArticleContentNotFoundException extends RuntimeException {

}

 

 

6. ReadArticleService 작성(게시글 읽기 기능 제공)

경로 : article.service > ReadArticleService.java

package article.service;

import java.sql.Connection;
import java.sql.SQLException;

import article.dao.ArticleContentDao;
import article.dao.ArticleDao;
import article.model.Article;
import article.model.ArticleContent;
import jdbc.connection.ConnectionProvider;

public class ReadArticleService {

	private ArticleDao articleDao = new ArticleDao();
	private ArticleContentDao contentDao = new ArticleContentDao();
	
	public ArticleData getArticle(int articleNum, boolean increaseReadCount) {
		try (Connection conn = ConnectionProvider.getConnection()){
			Article article = articleDao.selectById(conn, articleNum);
			if (article == null) {
				throw new ArticleNotFoundException();
			}
			ArticleContent content = contentDao.selectById(conn, articleNum);
			if (content == null) {
				throw new ArticleContentNotFoundException();
			}
			if (increaseReadCount) {
				articleDao.increaseReadCount(conn, articleNum);
			}
			return new ArticleData(article, content);
		} catch (SQLException e) {
			throw new RuntimeException(e);
		}
	}
}

 

7. ReadArticleHandler 작성

경로 : article.command > ReadArticleHandler.java

package article.command;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import article.service.ArticleContentNotFoundException;
import article.service.ArticleData;
import article.service.ArticleNotFoundException;
import article.service.ReadArticleService;
import mvc.command.CommandHandler;

public class ReadArticleHandler implements CommandHandler {

	private ReadArticleService readService = new ReadArticleService();

	@Override
	public String process(HttpServletRequest req, HttpServletResponse res) 
			throws Exception {
		String noVal = req.getParameter("no");
		int articleNum = Integer.parseInt(noVal);
		try {
			ArticleData articleData = readService.getArticle(articleNum, true);
			req.setAttribute("articleData", articleData);
			return "/WEB-INF/view/readArticle.jsp";
		} catch (ArticleNotFoundException | ArticleContentNotFoundException e) {
			req.getServletContext().log("no article", e);
			res.sendError(HttpServletResponse.SC_NOT_FOUND);
			return null;
		}
	}

}

 

8. commandHandlerURI.properties 수정. ReadArticleHandler가 /article/read.do 요청을 처리하도록 매핑 설정에 추가한다. 

/join.do=member.command.JoinHandler
/login.do=auth.command.LoginHandler
/logout.do=auth.command.LogoutHandler
/changePwd.do=member.command.ChangePasswordHandler
/article/write.do=article.command.WriteArticleHandler
/article/list.do=article.command.ListArticleHandler
/article/read.do=article.command.ReadArticleHandler

 

9. jsp에서 내용 출력을 위한 커스텀 태그(pre.tag) 구현 (줄바꿈 등 최대한 입력내용을 그대로 보여주기 위한 조치.)

경로 :  WebContent > WEB-INF > tags > pre.tag

<%@ tag body-content="empty" pageEncoding="utf-8" %>
<%@ tag trimDirectiveWhitespaces="true" %>
<%@ attribute name="value" type="java.lang.String" required="true"%>
<%
	value = value.replace("&", "&amp;");
	value = value.replace("<", "&lt;");
	value = value.replace(" ", "&nbsp;");
	value = value.replace("\n", "\n<br>");
%>
<%= value %>

 

10. readArticle.jsp 구현

경로 :  WebContent > WEB-INF > view > readArticle.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="u" tagdir="/WEB-INF/tags" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>게시글 읽기</title>
</head>
<body>
<table border="1" width="100%">
<tr>
	<td>번호</td>
	<td>${articleData.article.number}</td>
</tr>
<tr>
	<td>작성자</td>
	<td>${articleData.article.writer.name}</td>
</tr>
<tr>
	<td>제목</td>
	<td><c:out value='${articleData.article.title}' /></td>
</tr>
<tr>
	<td>내용</td>
	<td><u:pre value='${articleData.content}'/></td>
</tr>
<tr>
	<td colspan="2">
		<c:set var="pageNo" value="${empty param.pageNo ? '1' : param.pageNo}" />
		<a href="list.do?pageNo=${pageNo}">[목록]</a>
		<c:if test="${authUser.id == articleData.article.writer.id}">
		<a href="modify.do?no=${articleData.article.number}">[게시글수정]</a>
		<a href="delete.do?no=${articleData.article.number}">[게시글삭제]</a>
		</c:if>
	</td>
</tr>
</table>

</body>
</html>

11. 테스트 

 

다음 글

게시글 수정 기능 구현

https://nullgoyatten.tistory.com/27

JSP & Servlet 게시판 구현하기(게시글 내용 수정)