Dear Sven, I am running into this exact some problem in Ubuntu 14.04. I have R 3.1.1 freshly installed and OpenJDK 7 (I do not need BLAS, as far as I know). Trying to install rj and rj.dg I get the exact same error messages as you were getting "Error: cannot determine complete Java config". Were you able to solve this and install these packages? Thank you, Lu?s