[JSP] context-param을 사용하여 게시판 만들기

Jeini·2023년 5월 8일

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✔️ 객체와 객체의 기능을 java파일로 만들어준다.

✏️ Comment.java

package kr.ac.green;

public class Comment {
	private String writer;
	private String value;
	
	public Comment() {}
	public Comment(String writer, String value) {
		super();
		this.writer = writer;
		this.value = value;
	}
	
	public String getWriter() {
		return writer;
	}
	public void setWriter(String writer) {
		this.writer = writer;
	}
	public String getValue() {
		return value;
	}
	public void setValue(String value) {
		this.value = value;
	}
}

✏️ DataManager.java

package kr.ac.green;

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Map;
import java.util.Vector;
import javax.servlet.ServletContext;

public class DataManager {
	private static ServletContext application;
	
    // nameList 생성
	public static void setApplication(ServletContext app) {
		if(application == null) {
			application = app;
		}
		
		Map<String, String> nameList = (Map<String,String>)application.getAttribute("nameList");
		if(nameList == null) {
			nameList = new Hashtable<String, String>();
			
			Enumeration<String> names = application.getInitParameterNames();
			while(names.hasMoreElements()) {
				String name = names.nextElement(); // f1, f2,f3,f4
				nameList.put(name, application.getInitParameter(name)); // map에다가 넣어줌
			}
			application.setAttribute("nameList", nameList);
		}
	}
	
    // cmtList 가져오기
	public static Vector<Comment> getCmtList(String code) {
		Map<String, Vector<Comment>> cmtList = (Map<String, Vector<Comment>>)application.getAttribute("cmtList");
		
		if(cmtList == null) {
			cmtList = new Hashtable<String, Vector<Comment>>();
			application.setAttribute("cmtList", cmtList);
		}
		
		Vector<Comment> list = cmtList.get(code);
		if(list == null) {
			list = new Vector<Comment>();
			cmtList.put(code, list);
		}
		return list;
	}
	
    // 해당하는 이름 가져오기
	public static String getName(String code) {
		Map<String, String> nameList =
		(Map<String, String>)application.getAttribute("nameList");
		return nameList.get(code);
	}
	
    // cmt 추가하기
	public static void addCmt(String code, Comment cmt) {
		getCmtList(code).add(cmt);
	}
}

✏️ web.xml

✔️ application 초기화 파라미터 설정

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0">
  <display-name>04_27</display-name>
  <context-param>
  	<param-name>f1</param-name>
  	<param-value>춘식</param-value>
  </context-param>
  <context-param>
  	<param-name>f2</param-name>
  	<param-value>라이언</param-value>
  </context-param>
  <context-param>
  	<param-name>f3</param-name>
  	<param-value>콘</param-value>
  </context-param>
  <context-param>
  	<param-name>f4</param-name>
  	<param-value>고영희</param-value>
  </context-param>
</web-app>

✏️ template.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ page import="kr.ac.green.*" %>
<%
	DataManager.setApplication(application);
	String param = request.getParameter("code");
	String code = (param != null) ? param : "f1";
%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>template.jsp</title>
</head>
<body>
	<table border="1" width="80%">
		<tr>
			<td colspan="2">
				<jsp:include page="logo.jsp"/>
			</td>
		</tr>
		<tr>
			<td>
				<jsp:include page="menu.jsp"/>
			</td>
			<td>
				<jsp:include page="contents.jsp">
					<jsp:param name="code" value="<%= code %>" />
				</jsp:include>
			</td>
		</tr>
	</table>
</body>
</html>

✏️ menu.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ page import="java.util.*" %>
- Menu -
<br>
<ul>
	<%
		Map<String, String> nameList = (Map<String, String>)application.getAttribute("nameList");
		Set<String> names = nameList.keySet();
		for(String name :names) {		
	%>
	<li><a href="template.jsp?code=<%=name%>"><%=nameList.get(name) %></a></li>
	<%
		}
	%>
</ul>

✏️ logo.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ page import="java.util.*" %>
<%
	Map<String, String> nameList = (Map<String, String>)application.getAttribute("nameList");
%>
<h1>F<%= nameList.size() %>팬페이지 </h1>

✏️ contents.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ page import="java.util.*" %>
<%@ page import="kr.ac.green.*" %>
<%
	String code = request.getParameter("code");
	Vector<Comment> list = DataManager.getCmtList(code);
%>
<h1><%= DataManager.getName(code) %></h1>
<form action="save.jsp" method="post">
	메세지 : <input type="text" name="cmt" />
	<br>
	작성자 : <input type="text" name="writer" />
	<br>
	<input type="hidden" name="code" value="<%= code %>" />
	<input type="submit" value="등록" />
	<hr>
	<table>
		<tr>
			<th>번호</th>
			<th>내용</th>
			<th>작성자</th>
		</tr>
		<%
			for(int i=list.size()-1; i>=0; i--) {
				Comment cmt = list.get(i);
		%>
		<tr>
			<td><%= i+1 %></td>
			<td><%= cmt.getValue() %></td>
			<td><%= cmt.getWriter() %></td>
			
		</tr>
		<%
			}
		%>
	</table>
</form>

✏️ save.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ page import="kr.ac.green.*" %>
<%
	request.setCharacterEncoding("utf-8");

	Comment cmt = new Comment(
		request.getParameter("writer"),
		request.getParameter("cmt")
	);
	String code = request.getParameter("code");
	DataManager.addCmt(code, cmt);
	
	response.sendRedirect("template.jsp?code=" + code);
%>