<%@ page contentType="text/html" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'index.jsp' starting page</title>
</head>
<body>
<% //设置page属性范围，此属性只在当前的JSP有用
pageContext.setAttribute("name","柳");
pageContext.setAttribute("birthday",new Date());
%>
<%
String username =(String)pageContext.getAttribute("name");
Date userbirthday =(Date)pageContext.getAttribute("birthday");
%>
<h2>姓名：<%=username %></h2>
<h2>生日：<%=userbirthday %></h2>
<% //设置request属性范围，此属性只在服务器跳转有用
request.setAttribute("name2","柳1");
request.setAttribute("birthday2",new Date());
%>
<% //设置session属性范围，此属性只在一个浏览器中始终有用
session.setAttribute("name3","柳111");
session.setAttribute("birthday3",new Date());
%>
<% //设置 application 属性范围，此属性保存在服务器上
application.setAttribute("name4","柳11111");
application.setAttribute("birthday4",new Date());
%>
<jsp:forward page="page_02.jsp"/>
</body>
</html>
**************************************************************************************
<%@ page contentType="text/html" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'index.jsp' starting page222</title>
</head>
<body>
<%
String username =(String)pageContext.getAttribute("name");
Date userbirthday =(Date)pageContext.getAttribute("birthday");
%>
<h2>姓名：<%=username %></h2>
<h2>生日：<%=userbirthday %></h2>
<%
String username2 =(String)request.getAttribute("name2");
Date userbirthday2 =(Date)request.getAttribute("birthday2");
%>
<h2>姓名：<%=username2 %></h2>
<h2>生日：<%=userbirthday2 %></h2>
<%
String username3 =(String)session.getAttribute("name3");
Date userbirthday3 =(Date)session.getAttribute("birthday3");
%>
<h2>姓名：<%=username3 %></h2>
<h2>生日：<%=userbirthday3 %></h2>
<%
String username4 =(String)application.getAttribute("name4");
Date userbirthday4 =(Date)application.getAttribute("birthday4");
%>
<h2>姓名：<%=username4 %></h2>
<h2>生日：<%=userbirthday4 %></h2>
</body>
</html>
从javax.servlet.jsp.PageContext类中可以发现，可以指定page属性的范围
1. public static final int PAGE_SCOPE page属性范围，默认
2. public static final int REQUEST_SCOPE request属性范围
3. public static final int SESSION_SCOPE session属性范围
4. public static final int APPLICATION_SCOPE application属性范围
pageContext.setAttribute("name","chen",pageContext.REQUEST_SCOPE);
request 主要作用是接收客户端发送来的请求，
request是javax.servlet.http.HttpServletRequest接口的实例化对象
定义如下: public interface HttpServletRequest extends ServletRequest
