Whats the best way to resolve dependencies between Java projects?

Question

I think most of you will know, programmers often reuse code from other software. I think, most of the time it is a good idea. But if you use code from another project your program depends on the other project.

I my current case I got three java projects A, B and C. Now A uses B and B uses C. I'm using eclipse IDE and added B to the buildpath of A and C to the buildpath of B. Now there is an compiler error that A can't resolve something from C. So I have to add C to the buildpath of B.

So what is the best way, to resolve the dependencies while keeping your programm as independent as possible from other projects?

I would like to know is in general and in reference to my current situation. Are there better ways to do this? I.e. there are classpath settings in the launch / debug configuration view, but I think they won't help at compile time.

Thanks in advance.

Answer 1

This sounds like part of the problem set fixed by Maven. Using Maven and Eclipse, namely m2eclipse, you can have projects use other projects and all the dependency resolution is handled for you.

Answer 2

It sounds to me like you're doing what you have to without incorporating a dependency management tool like Ivy or Maven, which provide you the capability of "transitive dependency management". With either of these tools you can just specify that A depends on B and B depends on C and they will automatically know that A is going to need C as well.

The advantages of Maven (this is what I have experience in) also comes into play when it's time to package your projects for deployment since it can easily gather all of those dependencies (all the way down the hierarchy) and place them together into a distribution folder or a fat JAR that contains all of your dependencies. It takes some reading and set-up time to get into a tool like Maven, but it does make the task of managing your dependencies a whole lot easier, especially as they grow.