<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<%-- <!-- 静态获取 -->
<c:out value="helloworld"></c:out>
<!-- 动态获取 -->
<%
request.getSession().setAttribute("username", "lili");
%>
<c:out value="${3/2} "></c:out>
<%
String username="username";
String username1="";
request.setAttribute("username1", username1);
//放进requestScope对象里，用EL表达式取
request.setAttribute("username", username);
%>
<!-- false -->
<c:out value="${empty username }"></c:out><br>
<!-- true -->
<c:out value="${empty username1 }"></c:out><br>
<!-- true -->
<c:out value="${empty user }"></c:out><br>
<!-- 使用out标签输出常量 -->
<c:out value="hello World"></c:out><br>
<!-- 使用out标签输出变量 -->
<%
request.getSession().setAttribute("name", "li");
%>
<c:out value="${name }"></c:out><br>
<!-- default属性的使用 -->
<c:out value="${name1 }" default="error"></c:out><br>
<!-- escapeXml="true属性设置是否转义，默认为true不转义-->
<c:out value="<out标签>" escapeXml="false"></c:out>
<!-- 表达式控制标签set标签，存值到scope中 -->
<c:set value="today" var="day" scope="session"></c:set><br>
<!-- 输出day，值应该是today -->
<c:out value="${day }"></c:out>
<!-- 表达式控制标签set标签，存值到scope中 -->
<c:set var="age" scope="application">eleven</c:set><br>
<!-- 输出day，值应该是today -->
<c:out value="${age }"></c:out>
<!-- 存值到javabean中 -->
<!-- 通过set向Person属性赋值 -->
<!-- 赋值和输出都要用EL表达式 --> --%>
<jsp:useBean id="person" class="com.imooc.entity.Person" ></jsp:useBean>
<c:set target="${person}" property="age2" value="12"></c:set>
<%-- <c:out value="${person[age2]}"></c:out> --%>
</body>
</html>
