JGraphX is a Java Swing diagramming (graph visualisation) library licensed
under the BSD license.  It provides functionality for visualisation and
interaction with node-edge graphs (not charts).  It also includes
functionality like XML stencils support, various import/export and layouting
(automatically node/edge positioning).

Note: JGraphX is not actively developed nowadays.

WWW: https://github.com/jgraph/jgraphx