(1)Core标签库
<c:out>
jstl1.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%><!-- 引入JSTL核心标签库 --> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>JSTL标签库</title> </head> <body> <!-- escapeXml默认值为true --> <c:out value="小小的太阳" escapeXml="true"></c:out><br> <!-- param中不存在name属性,value的值为 null,通过default属性输出默认值 --> <c:out value="${param.name}" default="unknown"></c:out><br> <!-- 由于escapeXml设置为false,此时不转义html,因此5秒后跳转到百度页面 --> <c:out value="${param.name}" escapeXml="false"> <!-- 也可以通过标签体输出默认值 --> <meta http-equiv="refresh" content="5;url=http://www.baidu.com"/> </c:out><br> </body> </html>
访问:http://localhost:8080/JavaWeb1/jstl1.jsp。5秒后跳转到百度页面
加参数,访问:http://localhost:8080/JavaWeb1/jstl1.jsp?name=xxdty
此时,${param.name}不为null,所以输出${param.name}的值
<c:set>
jstl2.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" import="java.util.*"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%><!-- 引入JSTL核心标签库 --> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>JSTL标签库</title> </head> <body> <!-- 属性名为name,值为xxdty,在session域中 --> <c:set var="name" value="xxdty" scope="request"></c:set> <c:out value="${requestScope.name }"></c:out><br> <!-- 也可以通过标签体为属性赋值 --> <c:set var="sex" scope="session">man</c:set> <c:out value="${sessionScope.sex }"></c:out><br> <!-- 为JavaBean属性赋值 --> <jsp:useBean id="user" class="zh.el.demo.User" scope="page"></jsp:useBean><!-- 创建user对象 --> <c:set target="${pageScope.user }" property="name" value="小龙女"></c:set> <c:set target="${pageScope.user }" property="age" value="18"></c:set> <c:out value="${pageScope.user.name }"></c:out><br> <c:out value="${pageScope.user.age }"></c:out><br> <!-- 为Map集合属性赋值 --> <% Map<String,String> map = new HashMap<String,String>(); request.setAttribute("map", map); %> <c:set target="${requestScope.map }" property="man" value="姬如雪"></c:set> <c:set target="${requestScope.map }" property="woman" value="女帝"></c:set> <c:out value="${requestScope.map.man }"></c:out><br> <c:out value="${requestScope.map.woman }"></c:out><br> </body> </html>
访问:http://localhost:8080/JavaWeb1/jstl2.jsp
<c:remove>
jstl3.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%><!-- 引入JSTL核心标签库 --> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>JSTL标签库</title> </head> <body> <c:set var="company" value="HW" scope="request"></c:set> <c:set var="school" value="JH" scope="request"></c:set> <c:out value="${requestScope.company }"></c:out><br> <c:out value="${requestScope.school }"></c:out><br> <!-- 移除属性 --> <c:remove var="company" scope="request"/> <%-- <c:remove var="school" scope="request"/> --%> <c:out value="${requestScope.company }"></c:out><br> <c:out value="${requestScope.school }"></c:out><br> </body> </html>
访问:http://localhost:8080/JavaWeb1/jstl3.jsp
<c:remove>
jstl4.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%><!-- 引入JSTL核心标签库 --> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>JSTL标签库</title> </head> <body> <!-- 捕获的异常对象以指定名称保存在page域 --> <c:catch var="myException"> <% int i = 1 / 0; %> </c:catch> <c:out value="${pageScope.myException }"></c:out><br> </body> </html>
访问:http://localhost:8080/JavaWeb1/jstl4.jsp
<c:if>
jstl5.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%><!-- 引入JSTL核心标签库 --> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>JSTL标签库</title> </head> <body> <c:set var="a" value="1" scope="page"></c:set> <c:if test="${a eq 1 }" var="a" scope="page"> 逻辑表达式为真 </c:if> </body> </html>
访问:http://localhost:8080/JavaWeb1/jstl5.jsp
<c:choose>、<c:when>、<c:otherwise>
jstl6.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%><!-- 引入JSTL核心标签库 --> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>JSTL标签库</title> </head> <body> <c:choose> <c:when test="${empty param.job}"> unknown job </c:when> <c:when test="${param.job eq 'boss' }"> it is a boss! </c:when> <c:otherwise> it is not a boss! </c:otherwise> </c:choose> </body> </html>
<c:forEach>
(2)Functions标签库