<%--程序input.jsp--%>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head> <title>输入页面</title> </head>
<request.setCharacterEncoding("UTF-8");>
<body>
<request.setCharacterEncoding("UTF-8");>
<form action="sum.jsp"method="post">
<table>
<tr><td>数据1：</td><td><input name="shuju1"></td></tr>
<tr><td>数据2：</td><td><input name="shuju2"></td></tr>
<tr><td colspan="2"align="center"><input type="submit"value="提交"></td></tr>
</table>
</form>
</body>
</html>
<%--程序sum.jsp--%>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@page import="java.lang.*" %>
<html>
<head> <title>和页面</title> </head>
<body>
<%String str1=request.getParameter("shuju1");
String str2=request.getParameter("shuju2");
double s1=Double.parseDouble(str1);
double s2=Double.parseDouble(str2);
double s3=s1+s2;
request.setAttribute("st1",s1);
request.setAttribute("st2",s2);
request.setAttribute("st3",s3);
%>
<jsp:forward page="output.jsp"/>
</body>
</html>
<%--程序output.jsp--%>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<head> <title>输出页面</title> </head>
<body>
利用getAttribute方法获取利用setAttribute方法保存的值，并显示！<br>
<%Double a1=(Double)request.getAttribute("st1");
Double a2=(Double)request.getAttribute("st2");
Double a3=(Double)request.getAttribute("st3");
%>
<%=a1 %>+<%=a2 %>=<%=a3 %><br>
利用getParameter方法获取请求参数，并显示！<br>
<%String s1=request.getParameter("shuju1");
String s2=request.getParameter("shuju2");
%>
<%=s1 %>+<%=s2 %>=<%=a3 %><br>
</body>
</html>
原文：http://www.cnblogs.com/www-x/p/7778030.html