What is the best way to migrate an existing messy

Question

I joined a new company about a month ago. The company is rather small in size and has pretty strong "start-up" feel to it. I'm working as a Java developer on a team of 3 others. The company primarily sells a service to for businesses/business-type people to use in communicating with each other.

One of the main things I have been, and will be working on, is the main website for the company - from which the service is sold, existing users login to check their service and pay their bills, new users can sign up for a trial, etc. Currently this is a JSP application deployed on Tomcat, with access to a database done thru a persistence layer written by the company itself.

A repeated and growing frustration I am having here (and I'm pretty happy with the job overall, so this isn't an "oh no I don't like my job"-type post) is the lack of any larger design or architecture for this web application. The app is made up of several dozen JSP pages, with almost no logic existing in Servlets or Beans or any other sort of framework. Many of the JSP pages are thousands of lines of code, they jsp:include other JSP pages, business logic is mixed in with the HTML, frequently used snippets of code (such as obtaining a web service connection) is cut and paste rather than reused, etc. In other words, the application is a mess.

There have been some rumblings within the company of trying to re-architect this site so that it fits MVC better; I think that the developers and higher-ups are beginning to realize that this current pattern of spaghetti code isn't sustainable or very easily scalable to add more features for the users. The higher-ups and developers are wary of completely re-writing the thing (with good reason, since this would mean several weeks or months of work re-writing existing functionality), but we've had some discussions of (slowly) re-writing certain areas of the site into a new framework.

What are some of the best strategies to enable moving the application and codebase into this direction? How can I as a developer really help move this along, and quickly, without seeming like the jerk-y new guy who comes into a job and tells everyone that what they've written is crap? Are there any proven strategies or experiences that you've used in your own job experience when you've encountered this sort of thing?

Answer 1

This is harder to do in applications that are only in maintenance mode because it is hard to convince management that rewriting something that is already 'working' is worth doing. I would start by applying the principles of MVC to any new code that you are able to work on (ie. move business logic to something akin to a model, put all your layout/view code in one place)

As you gain experience with new code in MVC you can start seeing opportunities to change the existing code subtly so that it also falls in line. It can be a very slow process, but if you can show the benefits of this way of doing it then you will be able to convince others and get the entire team on board.

Answer 2

I would agree with the slow refactoring approach; for example, take that copy-and-pasted code and extract it into whatever the appropriate Java paradigm is (a class, perhaps? or better yet, use an existing library?). When your code is really clean and terse, yet still lacking in overall architectural strategy, then you'll be able to make things fit into an overall architecture much more easily.