Design for defining graphs or flowing structures

Question

I'm trying to create a system for representing and designing graphs in an easy way. That means it should be easy to create some graphical representation from the data structure but it should also be easy to store the structure and do easy calculation on it. Easy calulations in this sence are questions like which nodes are the next nodes from a given node in the graph.

Is there some nice way to define stuff like this in xml or database structures? Later would be easier to edit.

Is there maybe already some good java library abstract enough to support my problems?

I'm trying to define a production process which can also have cycles (these cylces are not so important and could be modeled differently), but it feels kind of weird having to make these fundamental design decisions when this problem is so generic.

Answer 1

JUNG - http://jung.sourceforge.net/, may be a good solution for you. It's pretty extensible and has visualization, graph algorithm support etc

Answer 2

neo4j is the "standard" graph database (see also). you can abstract away from a particular implementation (so that you can change the database without changing you code) using blueprints.

alternatively, if the database part is not so important, a library like jgrapht (i wasn't aware of jung, from chris's answer, but it looks similar) gives you access to the usual algorithms for in-memory structures.

[neo4j licencing]