JSTL - JSP 표준 태그 라이브러리

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

<!-- * 실행순서 HTML → CSS → JavaScript → 스크립틀릿(자바) → JSTL --> <!-- 스크립틀릿 변수 선언 --> <% String name = "김조은1"; %> <!-- 스크립틀릿 변수 출력 --> <% out.print(name); %> <hr> <!-- JSTL 변수 선언 --> <%-- <c:set var="변수명" value="값" /> --%> <c:set var="name" value="김조은2" /> <!-- JSTL 출력 --> <%-- <%= name %> --%> <!-- JSTL 선언한 변수는 표현문으로 사용불가 --> <c:out value="${name}" />

<!-- 단일 조건 --> <!-- c:if 는 단독 조건문만 가능 (else 개념이 없음) --> <c:if test="${number % 2 == 0}"> <c:out value="${number}" /> 은 짝수 입니다. </c:if> <c:if test="${number % 2 == 1}"> <c:out value="${number}" /> 은 홀수 입니다. </c:if>

!-- 다중 조건 --> <c:choose> <c:when test="${number % 2 == 0}"> <c:out value="${number}" /> 은 짝수 입니다. </c:when> <c:when test="${number % 2 == 1}"> <c:out value="${number}" /> 은 홀수 입니다. </c:when> <c:otherwise> 숫자가 아닙니다. </c:otherwise> </c:choose>

<h1>리스트 목록</h1> <% ArrayList<String> list = new ArrayList<String>(); list.add("아이템1"); list.add("아이템2"); list.add("아이템3"); // JAVA -> JSTL pageContext.setAttribute("list", list); %> <c:forEach items="${list}" var="item"> ${item} </c:forEach>

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

<% Date now = new Date(); pageContext.setAttribute("now", now); %> <h1><c:out value="${now}" /></h1> <h1><fmt:formatDate value="${now}" pattern="yyyy-MM-dd HH:mm:ss" /></h1> <h1><fmt:formatDate value="${now}" pattern="yyyy년 MM월 dd일 HH시 mm분 ss초" /></h1> <br> <h1><fmt:formatDate value="${now}" type="date" /></h1> <h1><fmt:formatDate value="${now}" type="time" /></h1> <h1><fmt:formatDate value="${now}" type="both" /></h1>

<h1><fmt:formatNumber value="12.4567" type="number" /></h1> <h1><fmt:formatNumber value="12.4567" type="currency" /></h1> <h1><fmt:formatNumber value="12.4567" type="percent" /></h1> <h1><fmt:formatNumber value="12.4567" pattern=".0" /></h1> <h1><fmt:formatNumber value="12.4567" pattern="₩0.00" /></h1>

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

DROP TABLE IF EXISTS board; CREATE TABLE board ( no INT AUTO_INCREMENT PRIMARY KEY COMMENT 'PK', id VARCHAR(64) NOT NULL UNIQUE COMMENT 'UK', title VARCHAR(255) NOT NULL COMMENT '제목', writer VARCHAR(100) NOT NULL COMMENT '작성자', content TEXT NOT NULL COMMENT '내용', created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP COMMENT '작성일', updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '수정일' ) COMMENT '게시판';

-- 샘플 데이터 추가 INSERT INTO board (id, title, writer, content ) VALUES (UUID(), '제목01', '작성자01', '내용01' ); INSERT INTO board (id, title, writer, content ) VALUES (UUID(), '제목02', '작성자02', '내용02' ); INSERT INTO board (id, title, writer, content ) VALUES (UUID(), '제목03', '작성자03', '내용03' ); INSERT INTO board (id, title, writer, content ) VALUES (UUID(), '제목04', '작성자04', '내용04' ); INSERT INTO board (id, title, writer, content ) VALUES (UUID(), '제목05', '작성자05', '내용05' ); -- 전체 실행 -- 데이터 조회 (alt+S) SELECT * FROM board;

<sql:setDataSource var="dataSource" url="jdbc:mysql://localhost:3306/aloha?serverTimezone=Asia/Seoul&allowPublicKeyRetrieval=true&useSSL=false" driver="com.mysql.cj.jdbc.Driver" user="aloha" password="123456" />

<sql:query var="list" dataSource="${dataSource}"> SELECT * FROM board </sql:query>

<table border="1"> <tr> <c:forEach var="col" items="${list.columnNames}"> <th><c:out value="${col}" /></th> </c:forEach> </tr> <c:forEach var="row" items="${list.rowsByIndex}"> <tr> <c:forEach var="col" items="${row}" varStatus="i"> <td> <c:out value="${col}"/> </td> </c:forEach> </tr> </c:forEach> </table>

<sql:update dataSource="${dataSource}" var="resultSet"> INSERT INTO board (title, writer, content) VALUES( ?, ?, ? ) <sql:param value="${title}" /> <sql:param value="${writer}" /> <sql:param value="${content}" /> </sql:update>

<sql:update dataSource="${dataSource}" var="resultSet"> UPDATE board SET title = ? ,writer = ? ,content = ? WHERE board_no = ? <sql:param value="${title}" /> <sql:param value="${writer}" /> <sql:param value="${content}" /> <sql:param value="${boardNo}" /> </sql:update>

<sql:update dataSource="${dataSource}" var="resultSet"> DELETE FROM board WHERE baord_no = ? <sql:param value="${boardNo}" /> </sql:update>

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

<h1>contains() 함수</h1> <p> 문자열 포함 여부 : ${fn:contains("Hello JSTL~!", "JSTL")} </p> <p> 문자열 포함 여부(대소문자 구분X) : ${fn:containsIgnoreCase("Hello JSTL~!", "jstl")} </p> <p> 문자열 포함 여부 : ${fn:contains("Hello JSTL~!", "JSP")} </p> <hr> <h1>toUpperCase(), toLowerCase() 함수</h1> <p> hello jstl~! : ${fn:toUpperCase("hello jstl~!")} </p> <p> Hello JSTL~! : ${fn:toLowerCase("Hello JSTL~!")} </p> <hr> <h1>length() 함수</h1> <p> 글자수 : Hello JSTL~! ( ${fn:length("Hello JSTL~!")} ) </p> <h1>split() 함수</h1> <c:set var="texts" value="${fn:split('Hello JSTL~!', ' ')}" /> <c:forEach var="i" begin="0" end="${fn:length(texts)-1}"> <p>texts[${i}] : ${texts[i]}</p> </c:forEach>