<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <%@page import="cn.itcast.Person"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>jstl+el表达式示例代码</title> </head> <body> <!-- 使用jstl+el表达式可以迭代list集合 --> <% Person p1 = new Person(); p1.setName("aa111"); Person p2 = new Person(); p2.setName("bb"); List list = new ArrayList(); list.add(p1); list.add(p2); request.setAttribute("list",list); %> <c:forEach var="person" items="${list}"> ${person.name }<br/> </c:forEach> <!-- 使用jstl+el表达式可以迭代map集合 --> <% Map map = new HashMap(); map.put("a","aaaaxxx"); map.put("b","bbbb"); map.put("c","cccc"); map.put("1","aaaa1111"); request.setAttribute("map",map); %> <br/> <%-- Set<Map.Entry> set = map.entrySet()--%> <c:forEach var="me" items="${map}"> ${me.key } = ${me.value }<br/> </c:forEach> <br/><br/> <c:if test="${user!=null}"> 欢迎您：${user.uesrname } </c:if> <c:if test="${user==null}"> 用户名：<input type="text" name="username"> 密码：<input type="password" name="password"> <input type="submit" value="登陆"> </c:if> </body> </html>