I have a customer who has an existing web application. This application is freely accessible. Now, he wants to commercialize the application.
The way to do this is by adding a system with subscriptions, so that a user has to log in to view the application. So far, no problem.
The problem comes in the fact that the existing web application was not developed by me, but by others. My client doesn't want to change the code in the existing application, he wants me, if possible, to create a new small web application around the existing one that handles session control.
This means that everytime a page of the existing application is accessed, a check needs to be performed by the new small application to see whether the user has allready a session, or not. If not, the user needs to login.
I have talked to someone who has done someting similiar, but that was in .net. It seems that on microsoft iis it is possible to configure that everytime a page of an application is accessed, a code snippet is automatcly run. This way the session check is performed.
The existing web application runs on tomcat webserver.
Can it be done? If so, how?
Thanks in advance,