JSP EL表达式 param、paramValues的使用：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
pageContext.setAttribute("pca", "pageContextAttribute");
//session.setAttribute("s", "session");
%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>008index</title>
</head>
<body>
<form action="index018.jsp" method="post" >
<input type="text" name = "name" value="inputName">
<input type="text" name = "age" value="28">
<input type="text" name = "food" value="apple">
<input type="text" name = "food" value="orange">
<input type="submit" value="submit" >
</form>
</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/";
pageContext.setAttribute("pca", "pageContextAttribute");
//session.setAttribute("s", "session");
%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>008index</title>
</head>
<body>
<p>param.name is : ${param.name }</p>
<p>param.age is : ${param.age }</p>
<p>param.food is : ${param.food }</p>
<p>paramValues.food is : ${paramValues.food }</p>
<p>paramValues.food[0] is : ${paramValues.food[0] }</p>
<p>paramValues.food[1] is : ${paramValues.food[1] }</p>
<p>使用paramValues得到的就是数组，即使提交的是单个信息也会得到数组</p>
<p>paramValues.name is : ${paramValues.name }</p>
<p>paramValues.name[0] is : ${paramValues.name[0] }</p>
<p>直接访问页面的header.Referer为空，其他页面提交过来的不为空</p>
<p>header.Referer is : ${header.Referer }</p>
<p>header["Referer"] is : ${header["Referer"] }</p>
<p>header["Content-Type"] is : ${header["Content-Type"] }</p>
</body>
</html>