JGraph is a free, mature, and robust Java Graphing framework that fully complies with Swing design principles. It contains all the graph visualization and interaction functionality you might expect in a graph library, including multiple views, layering, zoom, drag and drop, undo, automatic expanding and collapsing, routing, and layouts. You can create stunning workflow editors, call graphs, CAD tools, network diagrams, database visualization tools, and more. It can also be deployed on the server-side with a large range of image exporting functionality. It is fully documented and commercially supported.
This release makes a couple of minor fixes to the calculation of the dirty region when repainting using double buffering. If you were experiencing refresh issues after undos, these changes will resolve the problem.
URL: Java Graph Visualization and Layout