Regarding "Huge Modularity in Java" (http://stackoverflow.com/questions/23413746/radical-modularity-in-java)

Your idea does not look good, to be honest. You have a bad attitude against a huge codebase that works. You despise the previous work done on it. Each line of this "spaghetti" solved a problem and you are eager to get rid of this hidden knowledge. You talk about rewriting a huge application using patterns from another language(!) and tools none of you have mastered yet. You look not much experienced and yet you have such an authority in the project. Geez, you are asking stranges on the Internet about how to rewrite your huge app! I can't see it working the way you are describing it, sorry.

So, what could you do? Here are some suggestions: 1. before all, write tests. Do not stop and write a huge lot of tests - just start it. If you are going to work on a class, changing some behavior, write a test for this new behavior, only. This way you are going to create a (thin) safety net for future changes.


2. Discover what is really wrong in the app. "It's a mess" says nothing. Maybe the classes are so coupled. Then take one class and try to decouple it. Does it work? Take another one, and so on. Methods are too long? Write a class to factor it.

3. Do one, and only one step at a time. You are going to use Spring? Great! Set it up, use it to remove some new Foo() calls from the code. Forget separated repos, JARs and Gradle, only work on Spring. In the end, you should be able to start the application up and it will have to work as it worked before. If you cannot make the application work after only one step, why do you think you can do it after changing everything? (BTW, again, keep writing tests!)


Of course, much more should be done. The important thing is: if you are excited about it, it is probably a bad idea, refactoring is always painful. Also, some references: an excellent post of @joel-spolsky: joelonsoftware.com/articles/fog0000000069.html (he created StackOverflow, so you should obey him ;) ) and the videos of Uncle Bob (cleancoders.com). BTW, this question would probably not get closed in programmers.stackexchange.com.