국비 34일차 과제

과제 01) 없는 번호, 잘못된 번호 입력시
에러페이지가 출력되도록 해주세요!!!
+) web.xml 에러페이지 설정으로도 해보세요!~~

1번 코드

//FrontController.java
// 3. 응답(페이지 이동 등)
		//  1) 전달할 데이터가 있니? 없니? == 포워드? 리다이렉트?
		//  2) 어디로 갈까? == 경로
		if(forward == null) {
			// command 요청이 없는 경우
			try {
				response.sendRedirect("error/error.jsp");
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		else {
			if(forward.isRedirect()) {
				try {
					response.sendRedirect(forward.getPath());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			else {
				RequestDispatcher dispatcher=request.getRequestDispatcher(forward.getPath());
				try {
					dispatcher.forward(request, response);
				} catch (ServletException e) {
					e.printStackTrace();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
        
//BoardPageAction.jsp
	public ActionForward execute(HttpServletRequest request, HttpServletResponse response) {
		BoardDAO boardDAO = new BoardDAO();
		BoardDTO data = new BoardDTO();
		int bid = Integer.parseInt(request.getParameter("bid"));
		data.setBid(bid);
		data = boardDAO.selectOne(data);
		request.setAttribute("data", data);
		ActionForward forward = new ActionForward();
		if(data != null) {
			forward.setPath("board.jsp");
		}
		else {
			forward.setPath("error/error.jsp");			
		}
		forward.setRedirect(false);
		return forward;
	}

 

2번 web.xml 설정

 <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="https://jakarta.ee/xml/ns/jakartaee" xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_5_0.xsd" version="5.0">
<error-page>
  	<error-code>404</error-code>
  	<location>/error/404error.jsp</location>
  </error-page>
  
  <error-page>
  	<exception-type>java.lang.NullPointerException</exception-type>
  	<location>/error/500error.jsp</location>
  </error-page>
  
  <error-page>
  	<error-code>500</error-code>
  	<location>/error/500error.jsp</location>
  </error-page>
  
  <error-page>
  	<exception-type>java.lang.NumberFormatException</exception-type>
  	<location>/error/500error.jsp</location>
  </error-page>
  </web-app>

과제 02) 특정 글에 대한 댓글목록을 출력해주세요!~~~
+ 커스텀태그 활용해보기~~

1번 java 및 jsp

//	BoardPageAction.java
    @Override
	public ActionForward execute(HttpServletRequest request, HttpServletResponse response) {
		BoardDAO boardDAO = new BoardDAO();
		BoardDTO data = new BoardDTO();
		ReplyDAO replyDAO = new ReplyDAO();
		ReplyDTO replyDTO = new ReplyDTO();
		int bid = Integer.parseInt(request.getParameter("bid"));
		data.setBid(bid);
		replyDTO.setBid(bid);
		ArrayList<ReplyDTO> datas = replyDAO.selectAll(replyDTO);
		data = boardDAO.selectOne(data);

		request.setAttribute("data", data);
		request.setAttribute("datas", datas);
		ActionForward forward = new ActionForward();
		forward.setPath("board.jsp");
		if(data == null){
			forward.setPath("main.do");
		}
		forward.setRedirect(false);
		return forward;
	}

${data.bid}<br>
${data.title}<br>
${data.content}<br>
${data.writer}<br>
${data.regtime}<br>
${data.cnt}<br>
<hr>
<c:forEach var="reply" items="${datas}">
${reply.writer} | ${reply.content}<br>
</c:forEach>

<hr>
<a href="main.do">메인으로 돌아가기</a>

 

2번 커스텀 태그 사용

<%@ taglib tagdir="/WEB-INF/tags" prefix="mytag" %>

<mytag:board data="${data}"></mytag:board>
<hr>
<mytag:board_reply datas="${datas}"></mytag:board_reply>
<hr>
<a href="main.do">메인으로 돌아가기</a>

<!-- board.tag -->
<%@ tag language="java" pageEncoding="UTF-8"%>
<%@ attribute name="data" type="java.lang.Object"%>

${data.bid}<br>
${data.title}<br>
${data.content}<br>
${data.writer}<br>
${data.regtime}<br>
${data.cnt}<br>

<!-- board_reply.tag -->
<%@ tag language="java" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ attribute name="datas" type="java.lang.Object"%>

<c:forEach var="reply" items="${datas}">
${reply.writer} | ${reply.content}<br>
</c:forEach>