<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>el隐式对象</title>
</head>
<body>
${pageContext } <!-- pageContext.findAttribute("name") -->
<br/>
<br/>---------------从指定的page域中查找数据------------------------<br/>
<%
pageContext.setAttribute("name","aaa"); //map
%>
${pageScope.name }
<br/>---------------从request域中获取数据------------------------<br/>
<%
request.setAttribute("name","bbb"); //map
%>
${requestScope.name }
<br/>---------------从session域中获取数据------------------------<br/>
${sessionScope.user }
<br/>--------------获得用于保存请求参数map，并从map中获取数据------------------------<br/>
<!-- http://localhost:8080/day12/3.jsp?name=aaa -->
${param.name }
<!-- 此表达式会经常用在数据回显上 -->
<form action="${pageContext.request.contextPath }/servlet/RegisterServlet" method="post">
<input type="text" name="username" value="${param.username }">
<input type="submit" value="注册">
</form>
<br/>--------------paramValues获得请求参数 //map{"",String[]}------------------------<br/>
<!-- http://localhost:8080/day12/3.jsp?like=aaa&like=bbb -->
${paramValues.like[0] }
${paramValues.like[1] }
<br/>--------------header获得请求头------------------------<br/>
${header.Accept }
${header["Accept-Encoding"] }
<br/>--------------获取客户机提交的cookie------------------------<br/>
<!-- 从cookie隐式对象中根据名称获取到的是cookie对象,要想获取值，还需要.value -->
${cookie.JSESSIONID.value } //保存所有cookie的map
<br/>--------------获取web应用初始化参数------------------------<br/>
${initParam.xxx } //servletContext中用于保存初始化参数的map
${initParam.root }
</body>
</html>
