（1）ch03_9_input.jsp
<body>
<form action="ch03_9_sum.jsp"method="post">
数据1:<input type="text"name="shuju1"><br>
数据2:<input type="text"name="shuju2"><br>
<input type="submit"value="提交">
</body>
（2）ch03_9_sum.jsp
<body>
<%String str1=request.getPamameter("shuju1");
String str2=request.getPamameter("shuju2");
double s1=Double.getPamameter("str1");
double s2=Double.getPamameter("str2");
double s3=s1+s2;
request.setAttribute("str1",s1);
request.setAttribute("str2",s2);
request.setAttribute("str3",s3);
%><jsp:forward page="ch03_9_output.jsp"></jsp:forward>
</body>
（3）ch03_9_output.jsp
<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("str1");
Double a2=(Double)request.getAttribute("str2");
Double a3=(Double)request.getAttribute("str3");
%><%=a1%>+<%=a2%>=<%=a3%><br>
利用getPamameter方法获取请求参数，并显示！<br>
<%String s1=request.getPamameter("shuju1");
String s2=request.getPamameter("shuju2");
%><%=s1%>+<%=s2%>=<%=a3%><br>
</body>