i've done this on heroku recently (where you're also not root !) and there are simple ways to do so.
first, you should build statically linked opencv libs, so your opencv-java.so does no more depend on further opencv so's:
cmake -DBUILD_SHARED_LIBS=OFF
then, you're free to change the install location to any place, that does not need root privileges (e.g. your home folder), like:
cmake -DCMAKE_INSTALL_PREFIX=/opt/opencv
(that's just an example !)
in the end, like this you will only need the opencv-java.so and opencv_java.jar.
you could even skip the make install
step, and copy those files manually from your build folder.