Java EE (Java Enterprise Edition) General Discussion

Hi guys!!
I think my prob is a common one, but i dint found any satisfactory answer.

Here its:
We developed a application in JSP mainly, without following MVC(surprisingly). It shows all the URL's and parameters straight forward. Which i am assigned to change, as any one can alter the URL and access things.

Now i want to use any sort of URL Encryption or Encoding. Like most of the standard sites are using some sort of URL encoding so that URL seems non-sense to the users. But i dont have any idea for that. If u guys can help in any way.

I am also interested in knowing, how much of rework will be needed, if any idea, as i mentioned we r not using any MVC, so no Controller :(.

Thanks in advance