If you were using JGraph, you should give a try to JGraphT which is designed for algorithms. One of its features is visualization using the JGraph library. It’s still developed, but pretty stable. I analyzed the complexity of JGraphT algorithms some time ago. Some of them aren’t the quickest, but if you’re going to implement them on your own and need to display your graph, then it might be the best choice. I really liked using its API, when I quickly had to write an app that was working on graph and displaying it later.