how to add new optional parameter to JSP

Hi,

I have an old JSP project in which the request is sent like this

http://myhost:8080/myjava/WBCM?triggername=sysmgrtest&cmd=mstrsysmgr&cmddelay=0&projname=

and is handled in the code at the end

This kind of URL is shared with many existing users. Now I need to add a new request parameter inpfilename

http://myhost:8080/myjava/myjsp?triggername=alpha&cmd=beta&cmddelay=0&projname=omega&inpfilename=abcdefg

but i need to make inpfilename as optional request parameter or else all the old URLs (100s of them) will have to be modified which is not possible

How can I do that ? in the following code to ensure that I can keep adding new request parameters but the OLD URLs don't break

thanks
-anshu


public static void handleRequest(HttpServletRequest req, HttpServletResponse res) throws IOException {

            //out = res.getWriter();
            //res.setContentType("text/plain");

            
            
            String paramName="";
            
            
            paramName = "cmd";
            commandType = req.getParameter(paramName);
            
            paramName = "triggername";
            triggerName = req.getParameter(paramName);
            
        paramName="cmddelay";
        commandDelay=Integer.parseInt(req.getParameter(paramName));
            
        paramName = "projname";
        projectName = req.getParameter(paramName);
       
       
            
      }