JSP jstl
https://www.javatpoint.com/jstl-function-tags
JSTL이란?
HTML 코드 내에 java 코드인 스크립틀릿 <%= student %>를 ${student}로, <%=if %>문을 <c:if>, <%=for%>문을 <c:forEach>로 대체하여 사용한다.
JSP - EL 표현식 문법과 사용 방법
EL(Expression Language)
foreach.jsp
<!-- jar파일 붙여 놓음 -->
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%
//배열을 만듬
String[] cities = {"Mumbai", "Singapore", "Philadelphia"};
//이페이에 있는 속성들을("이름으로", 이값들을 저장함)
pageContext.setAttribute("myCities",cities);
%>
<html>
<body>
<c:forEach var="tempCity" items = "${myCities}">
${tempCity} <br/>
</c:forEach>
</body>
</html>
foreach-student-test.jsp
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ page import = "com.jstlEx.jsp.tagdemo.Student" %>
<%@ page import = "java.util.*" %>
<%
//배열을 만듬
/* List<Student> student = new ArrayList<>();
Student student2 = new Student("John","Doe",false);
Student student3 = new Student("MaxWell","Johnson",false);
student.add(student2);
student.add(student3);
student.add(new Student("Marry","Public",true)) */;
Student[] student = new Student[3];
student[0] = new Student("John","Doe",false);
student[1] = new Student("MaxWell","Johnson",false);
student[2] = new Student("Marry","Public",true);
/* Student[] student = {(new Student("John","Doe",false)),
(new Student("MaxWell","Johnson",false)),
(new Student("Marry","Public",true))}; */
//이페이에 있는 속성들을("이름으로", 이값들을 저장함)
pageContext.setAttribute("mystudent",student);
%>
<html>
<head>
<meta charset="EUC-KR">
<title>Insert title here</title>
</head>
<body>
<c:forEach var="student2" items = "${mystudent}">
${student2.firstName} ${student2.getLastName()} ${student2.isGoldCustomer()} </br>
</c:forEach>
<table border = "2">
<tr>
<th>First Name</th>
<th>Last Name</th>
<th>Gold Customer</th>
<th>jstl core : if ,choose</th>
</tr>
<c:forEach var="student" items = "${mystudent}">
<tr>
<td>${student.firstName} </td>
<td>${student.getLastName()} </td>
<td><c:if test="${student.isGoldCustomer()}">
Special Discount
</c:if>
<c:if test="${!student.isGoldCustomer()}">
No offer
</c:if>
</td>
<td>
<c:choose>
<c:when test = "${'Marry' eq student.firstName}">
First Name is Marry
</c:when>
<c:otherwise>
NoNoNo
</c:otherwise>
</c:choose>
</td>
</tr>
</c:forEach>
</table>
</body>
</html>function-test.jsp
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<html>
<body>
<c:set var="data" value="Lovejava"/>
Length of the string <b>${data}</b> : ${fn:length(data)}
<br/><br/>
Uppercase version of the string : <b>${data}</b> : ${fn:toUpperCase(data)}
<br/><br/>
Does the string <b>${data}</b> Start with <b>
${fn:substring(data,0,4)}</b>? : ${fn:startsWith(data,"Love"")}
</body>
</html>split-join.jsp
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<html>
<body>
<%-- Here is the jsp comment --%>
<!-- Here is the html comment -->
<c:set var="data" value="Singapore,Toyko,Munbai,London"/>
<h2>N0.1</h2>
<c:forEach var= "test" items = "${data}">
${test}<br/>
</c:forEach>
<br/>
<h2>First Demo</h2>
<c:set var ="FirstDemo" value = "${fn:split(data,',')}"/>
<c:forEach var="i" items = "${FirstDemo}">
${i} <br/>
</c:forEach>
<h2>Second Demo</h2>
Result of joining : ${fn:replace(data,",","*")}
<br/> <br/>
<c:set var="j" value ="${fn:join(FirstDemo,'*')}"/>
Result of joining2 : ${j}
</body>
</html>i18n-messages-test.jsp
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
<!-- 변수선언 -->
<c:set var="theLocale"
value = "${not empty param.theLocale
? param.theLocale : pageContext.request.locale}"
scope="session"/>
<%-- {2>1 ? true : false } --%>
<fmt:setLocale value = "${theLocale}"/>
<fmt:setBundle basename = "com.jstlEx.jsp.tagdemo.i18n.resources.mylabels"/>
<html>
<body>
${pageContext.request.locale}
<a href="i18n-messages-test.jsp?theLocale=en_US">English (US)</a>|
<a href="i18n-messages-test.jsp?theLocale=es_ES">Spanish (ES)</a>|
<a href="i18n-messages-test.jsp?theLocale=de_DE">German (DE)</a>
<hr>
<fmt:message key="label.greeting"/> <br/><br/>
<fmt:message key="label.firstname"/> <i>John</i> <br/>
<fmt:message key="labal.lastname"/> <i>Doe</i> <br/><br/>
<fmt:message key="label.welcome"/> <br/>
<hr>
Selected locale: ${theLocale}
</br>
</body>
</html>
웹 개발자