Why is Runtime.getRuntime().exec() not working in JSP?

Question

Hi all,
I need to execute a command file from a JSP. I am using Tomcat 4.0.3.
Here is the code :
I just wanted to test if this will work, so tried to do run notepad.exe. But in my actual project, i need to run some other commands from a bat file or cmd file.
<%@ page import="java.util.*,java.io.*,java.net.*" %>
<%@ page import="java.sql.*" %>
<%@ page import="tryexec" %>
//tryexec is a class which has the same java statements as in this jsp
<%     
Runtime r = Runtime.getRuntime();
String s3 = "C:\\WINNT\\explorer.exe";
String s4 = "C:\\bin\\open.cmd"; //inside open.cmd file , i have "notepad.exe"
r.exec(s3);
r.exec(s4);
/*     tryexec c = new tryexec();
     c.execTo(); // doesn't work
%>
I have a html page , when i click a button there , it will call the above jsp , and this jsp will execute the command file.
If i run the above java statements using a simple java program, it works fine, it opens a notepad and explorer window. but if i do the same thing in jsp, why doesn't it work? Is there any security problem? no exception is shown . Is it a problem with tomcat?
I also tried to import the java class in jsp and call the function, but still didnt work.
Please let me know whats the problem, and how to execute command files from jsp.
Thanks
Priyha

Answer 1

It would work with Java coz u r working on the same machine as the java class file.
While in case of JSP, it is like connecting to a different machine (even if the server is running on the same machine). If you do something like "net send user message" command in JSP or something other executable (just to test), you would see it to work.
I hope you understand my point here.
Write back if you have any issues.
Regards
Aruneesh