[23.02.22]

EL(Expression Language)

• 표현언어 %= % => ${}
• 내장객체p ageScope, requestScope, sessionScope, applicationScope, param, paramValues
• 연산자 . , [], () 조건 ? 참 : 거짓, empty => null, 0
  +, -, *, / div, % mod
  && and, || or, ! not
  == eq, != ne, < lt, > gt, <= le, >= ge

String id=(String)session.getAttribute("id");

<%=id%>

(==)

${sessionScope.id} 

JSTL(JSP Standard Tag Library)

• JSP 표준 태그 함수

• 프로그램 설치 tomcat.apache.org
  
  다운받아서
  lib 폴더에 넣어주기
  
  
  상단에 입력, 가져와서 사용

• 변수선언
  <c:set>

• 조건
  <c:if>, <c:choose>, <c:when> <c:otherwise>

• 반복문
  <c:forEach>, <c:forTokens>

• 이동
  <c:redirect>, <c:url>, <c:import>, <c:param>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

=> 포맷 가져와서 사용할 때
날짜 포맷 <fmt:formatDate>, 숫자포맷 <fmt:formatNumber>, 한글 <fmt:requestEncoding>

• 헤더 login join 구현하기

<c:if test="${! empty sessionScope.id}">
<div id="login"><%=id %> => ${sessionScope.id} 님 | 
                <a href="MemberLogout.me">logout</a> | 
                <a href="MemberUpdateForm.me">update</a></div>	
</c:if>

<c:if test="${empty sessionScope.id}">
<div id="login"><a href="MemberLoginForm.me">login</a> | 
                <a href="MemberInsertForm.me">join</a></div>	
</c:if>

• 게시판 리스트 목록 불러오기

<table id="notice">
<tr><th class="tno">No.</th>
    <th class="ttitle">Title</th>
    <th class="twrite">Writer</th>
    <th class="tdate">Date</th>
    <th class="tread">Read</th></tr>

<c:forEach var="dto" items="${boardList}">

<tr onclick="location.href='BoardContent.bo?num=${dto.num}'"><td>${dto.num}</td>
    <td class="left">	
    
    <c:if test="${dto.re_lev > 0}">
    <c:set var="wid" value="${dto.re_lev*10}"></c:set>
    <img src="images/center/level.gif" width="${wid}" height="15">
 	<img src="images/center/re.gif"> 
 	</c:if>
    
     ${dto.subject}</td>
    <td>${dto.name}</td>
    <td><fmt:formatDate value="${dto.date}" pattern="yyyy.MM.dd"/>  </td>
    <td>${dto.readcount}</td></tr>	  

</c:forEach>
    
</table>