SOA（ish）架构，在哪里放置公共代码？

Question

we have a soa-ish architecture which looks like this

frontend            ->domain A ->db 
frontend->business A->domain B ->db
frontend            ->domain C ->db
frontend            ->domain A ->db 
frontend->business B->domain B ->db
frontend            ->domain C ->db

other app A
other app B

we also have other applications which are not part of this soa stack.

from time to time we have the following discussion/problem:

"i have code in domain A that is also useful in domain B but not in business services - where should i put the stuff with its tests".

let's assume the code is very abstract and domain agnostic, something very generic that could also be used by the "other" applications outside of soa.

so the question is:

a) put it in a "generic-domain-stuff" module which all domain inherit via maven dependencies. This will probably end up growing and growing until it is a mess….

b) create a module "generic-stuff" which can be used by soa and the "other" applications. This will probably lead to a lot of small maven modules….

c) duplicate the code until you have three use cases, then refactor to a) or b). This screems DRY (don't repeat yourself)

i have people with 10+ years of "enterprise" experience around me but we never seem to find a proper solution/answer to the always same problems :)

i would be interested in hearing you experiences

Answer 1

(b) should be the way to go. If the code/logic is so generic then it is best fit for a library. Application(s) needing this logic should use the library through maven (or any other dependency management mechanism). You should not allow one library to become a "god library". Break the library into smaller cohesive pieces as time passes. That way you can prevent it from growing too big and becoming a mess. Don't worry about many maven libraries - many small and cohesive libraries are better than one big monolithic "do it all" library.