JTS is your best free open source option. The method you are looking for in JTS is here
As far as commercial options, you have ESRI’s Java JNI version of their ArcObjects library which has a very robust Geometry Library. The interface on ESRI’s library is called ITopologicalOperator
If all you are trying to do is Geometric operations, JTS is your best option – it is an excellent library which has many ports to different languages. If, on the other hand, you are looking for an entire GIS system that does complex symbology, supports GIS workflows and multiuser editing, printing, etc etc, then I would start looking at the ESRI libraries.