How to approach shifting a Java Swing app to a Servlet ?

Question

I want to use the Model-View-Controller template while writing my Web App. The problem is, the Model part of the code has already been written in Swing. The Model code also must require the container to call its main method before any interaction with its servlets. So is there a way for me to specify the location of the main method in the Deployment Descriptor so that the container calls the main method and compiles the code, and then, keeps it running for the entire duration the server is running without in any way restarting or recompiling the model class in between.

Answer 1

To run initialization when a web app is loaded, you can either use the servlet's init method or a ServletContextListener. You can call the main method from either of those yourself.

Answer 2

Try looking into load-on-startup parameter of servlet in Deployment Descriptor (DD). Precisely, it will load that particular servlet on server start-up.

Moreover, you should read about request lifecycle, request/session/application context. And you must look into JSP (or any other popular technology) for creating V of MVC. How URL mapping works.

Main method is basically work as an entry point in our application. Whereas in web application there is no particular entry point. Or if there is you can think of a welcome page. You might also want to look into welcome-file-list parameter of DD.

Cheers.