JSP Standard Tag Library (JSTL)

1. JSP Standard Tag Library (JSTL) Internet Computing Laboratory @ KUT Youn-Hee Han

2. JSTL 기본 • 문법 <prefix:tagName attributes/> OR <prefix:tagName attributes> some body content </ prefix:tagName> 다운로드 하여 lib 디렉토리에 추가 Web root (2006777888) WEB-INF lib jstl.jar standard.jar classes Web Programming

3. JSTL 기본 • JSP에 taglib Directive 추가 • import into your JSP page each JSTL library that the page will reference. • taglib directives • core: <%@ taglib prefix="c" uri="http://java.sun.com/jstl/core" %> • Basic scripting functions such as loops, conditionals, and input/output • xml: <%@ taglib prefix="x" uri="http://java.sun.com/jstl/xml" %> • XML processing • fmt: <%@ taglib prefix="fmt" uri="http://java.sun.com/jstl/fmt" %> • Internationalization and formatting of values such as currency and dates • sql: <%@ taglib prefix="sql" uri="http://java.sun.com/jstl/sql" %> • Database access • fn: <%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %> • JSTL functions Web Programming

4. JSTL “Hello World” • JSTL 기본 예제 /2006777888/hellojstl.jsp <%@ page contentType = "text/html; charset=euc-kr" %> <%@ taglib prefix="c" uri="http://java.sun.com/jstl/core" %> Setting the value: "Hello World!" <c:set var="hello" value="Hello World!"/> <p/> <c:out value="${hello}"/> Web Programming

5. JSTL Sample • JSTL Example 1 <% if (list.size() > 0) { for (int i=0; i<list.size(); i++) { Data data = (Data) list.get(i); %> <%= data.getTitle() %> …<% } } else {%> 데이터가 없습니다.<% } %> <c:if test=“${!empty list}”> <c:forEach var=“data” list=“${list}”> ${data.title} <c:forEach> </c:if> <c:if test=“${empty list}”>데이터가 없습니다.</c:if> Web Programming

6. JSTL Sample • JSTL Example 2 <% String op1 = request.getParameter("option1"); if ( op1 != null ) { %> <b><%= op1 %><br></b> <% } %> <c:if test="${! empty param.option1}"> <b>${param.option1}<br></b> </c:if> • JSTL Example 3 <% Map likeMap = request.getParameterMap(); String[] like = (String[])likeMap.get("like"); for(int i=0; i<like.length;i++){ %> <b><%= like[i] %><br></b> <% } %> <c:forEach var="i" items="${paramValues.like}"> <b>${i}<br></b> </c:forEach> Web Programming

7. JSTL Sample • JSTL Example 4-1 <%@ page import="java.util.*"%> <p><h1>Customer Names</h1></p> <% List addresses = (List)request.getAttribute("addresses"); Iterator addressIter = addresses.iterator(); while(addressIter.hasNext()) { String addr = (String)addressIter.next(); if ((addr != null) && (addr.getLastName() != null) && (addr.getLastName().length() > 0)) { %> <%=addr.getLastName()%><br/> <% } else { %> N/A<br/> <% } } %> <p><h5>Last Updated on: <%=new Date()%></h5></p> Web Programming

8. JSTL Sample • JSTL Example 4-2 <%@ taglib prefix="c" uri="http://java.sun.com/jstl/core" %> <p><h1>Customer Names</h1></p> <c:forEach items="${addresses}" var="address"> <c:choose> <c:when test="${!empty address.lastName}" > <c:out value="${address.lastName}"/><br/> </c:when> <c:otherwise> N/A<br/> </c:otherwise> </c:choose> </c:forEach> <jsp:useBean id="now" class="java.util.Date" /> <p><h5>Last Updated on: <c:out value="${now}"/></h5></p> Web Programming

9. JSTL Sample • JSTL Example 5 <%@ page contentType = "text/html; charset=euc-kr" %> <%@ page isELIgnored="false" %> <%@ taglib prefix="c" uri="http://java.sun.com/jstl/core_rt" %> <c:set var="a" value="<B>ABC</B>" /> ${a}<BR> <c:out value="${a}"/><BR> <c:out value="${a}" escapeXml="true"/><BR> <c:out value="${a}" escapeXml="false"/><BR> <c:out value="${b}" escapeXml="false" default=“DEF" /> • JSTL Example 6 (교재 433page 소스코드를 JSTL 코드로 변환) <%@ page contentType = "text/html; charset=euc-kr" %> <%@ page isELIgnored="false" %> <%@ taglib prefix="c" uri="http://java.sun.com/jstl/core_rt" %> <c:set var="ids" value="<%= java.util.TimeZone.getAvailableIDs() %>" /> <c:forEach var="i" items="${ids}"> ${i}<BR> </c:forEach> Web Programming