According to the official page, rJava is a Low-level interface to Java VM very much like .C/.Call and friends. A strange error occurs while I try to load rJava insido RStudio.
Reason: image not found
According to the thread, starting RStudio and setting LD_LIBRARY_PATH variable from terminal can solve the problem.
$ LD_LIBRARY_PATH=/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home/jre/lib/server: open -a RStudio
You may make an alias for the command in ~/.bashrc.