You can try mefisto wrapper for recast4j.
You will find the links to it here.
I wrote a wiki for the demo at the demo website but you must understand that the demo has all the proper classes implemented to make the wrapper work in a game and just trying to use jme-recast4j will not work like the demo does without them.
You have to read all my posts and fully implement all those extra classes.
On the bright side, this example file contains every build type there is for procedural builds of recast4j,
https://github.com/MeFisto94/jme3-recast4j-demo/blob/52af8a0e1a9b26f03f326a9df8d3dd773a686f25/src/main/java/com/jme3/recast4j/demo/states/NavState.java as well as pathfinding for individual characters.
Those classes are in this folder of the repo.
https://github.com/MeFisto94/jme3-recast4j-demo/tree/52af8a0e1a9b26f03f326a9df8d3dd773a686f25/src/main/java/com/jme3/recast4j/demo
The DemoApplication.java file there is the only file that is specific to the demo itself. The rest are files that you will need in addition to the wrapper.
These files JmeInputGeomProvider, GeometryProviderBuilder2, RecastBuilder would allow you to probably exclude the wrapper library altogether and use recast4j instead. But that requires knowledge of recast4j and the wrapper to pull it off.
The thing about recast4j is it is only intended to be a java wrapper of the original recast project. As such, piotr only ported it up to that point where the project was abandoned. Recast was never intended to be used as anything more than a demo really so my work completes some of those generic features, allowing it to be used in jme proceduraly.
Ai is hard stuff. People get paid big money to do it. Its a field all in and of itself. You wont get what you want without alot of study and effort. There is no easy way I found.
Thats why I would love to find a solution thats like the holy grail of ai, just not seen anything to date like that.
I have spent a huge amount of time on it myself, maybe about 12 months in total, and would consider myself intermediate at best in using recast. Its one of those things that the more you use it the more you learn.
So, if you happen run across something easier, that is full featured and is maintained, let me know because it sure would be appreciated immensely.