FormFact.html
<!-- Servlet,
form data and validation -->
<html>
<head>
<title> Forms, servlet and
factorial</title>
<style>
h3{text-align:center}
</style>
<script
type="text/javascript" language="javascript">
function fnvalidate()
{
// User Name
Validation
var Num =
document.FN.f1.value;
if
(Num.toString().trim().length==0)
{
alert(
"Error...Enter number" );
document.FN.f1.focus()
;
return
false;
}
if( isNaN(Num))
{
alert(
"Invalid Number! Should have only digits." );
document.FN.f1.focus()
;
return
false;
}
return true;
}
</script>
</head>
<body>
<br/><h3> Factorial
Calculator </h3><br/><br/>
<center>
<form name="FN" method="get"
action="http://localhost:8088/WT/FactCalc" onsubmit="return
fnvalidate();">
<label> Enter Number :
</label>
<input
type="text" name="f1" />
<br/><br/>
<input
type="submit" />
<input
type="reset" />
</form>
</html>
FactCalc.java
import
java.io.*;
import
javax.servlet.*;
import
javax.servlet.http.*;
public class
FactCalc extends HttpServlet
{
int N;
public void init(ServletConfig sc)
{
}
public void service(HttpServletRequest
req, HttpServletResponse res) throws ServletException, IOException
{
res.setContentType("text/html");
PrintWriter pw =
res.getWriter();
N =
Integer.parseInt(req.getParameter("f1"));
int fact=1;
for(int i=1;i<=N;i++)
fact=fact*i;
pw.println("<html><body><center>");
pw.println("<h3>");
pw.println("Factorial of
"+N +" is "+fact);
pw.println("</h3>");
pw.println("</center></body></html>");
pw.close();
}
public void destroy()
{
}
}
