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.
Snapping to grid for more than MAXCELLS now works correctly. Rounding from double to int has been removed in BasicGraphUI.RootHandle.mouseDragged. Edge label positions have been changed to be placed relative to the vertex perimeters rather than the centers of the vertices. A window close event has been added to the EditorGraph example.
URL: Java Graph Visualization and Layout