Im switching too much between these "wrapper" frameworks so I think I should just concentrate on one and leave the others alone. Which should I go for in a servlet like enviroment? JNI, JNA or Swig? The only one I have "expirence" with is JNI. The rest Im playing around without getting it to work (Got JNA to work with helloworld)

why do you want to use them at all?

Servlets should rarely if ever do anything that requires such low level code that it can't be done entirely in Java, and when they do completely isolating that code from the servlet environment and calling it through some protocol (tcp connection, web service, whatever) is almost always far better than trying to force native code into a servlet application (or indeed any Java application).