Managing project dependencies in Eclipse

Hi, using Eclipse IDE i have two projects they both use each other's packages ... I get an eclipse error ... "a cycle was detected in a build path of a project eclipse" ... I can easily change this to a warning in eclipse, wondering if this can give run time problems

Thanks

Cycling dependencies are a maintenance nightmare.
I suggest you to move the code that created the cycle to a new project and make the other two depend on this one.

By using interface or abstract classes on the third object? i would think the needed code/classes can be made an abstract class in a third project then every class which needs it creates a local child class.. Say i have project A and Project B... Project A needs class bb from B and project B needs class aa from A, how do i implements this using third project?

This is where things get tricky and i personally struggle with deciding when to make a new project.
In your case, if i understood correctly (you talked about inheritance and then gave an example that didn't use that)m, It seems like you need a Project C that has class bb and aa in it and both Project A and B use that jar.

definitely project C is the sensible solution but may be tricky to implement as it will have some hibernate mappings involved .. i.e aa has a one to many relationship with bb ...!!!

if project c has both aa and bb then what's the issue?

the concept ain't correct perhaps ... C has to contain only generic hibernate classes and objects which any other new project should be able to use... So C as an abstract/generic project to contain HibernateUtils, GenericDAO + a specific generic class(es), in this case aa ... But aa will/may have relationship/mapped with other classes like bb, ee, ff from those respective projects B, E, F .. I think i may have confused you a bit .. but i will try figure out something, thanks a lot for your ideas, helped!!!