Why does rJava not work on Ubuntu 14.04 using OpenJDK 7?

Question

Hi I'm having issues with the rJava package from cran.

I have installed

sudo apt-get install openjdk-7-jdk
sudo apt-get install r-cran-rjava

and ran

sudo R CMD javareconf
# Java interpreter : /usr/bin/java
# Java version     : 1.7.0_55
# Java home path   : /usr/lib/jvm/java-7-openjdk-amd64/jre
# Java compiler    : /usr/bin/javac
# Java headers gen.: /usr/bin/javah
# Java archive tool: /usr/bin/jar

I then try to run R and load rJava and get the following error:

R
> library(rJava)
Error : .onLoad failed in loadNamespace() for 'rJava', details:
  call: dyn.load(file, DLLpath = DLLpath, ...)
  error: unable to load shared object '/usr/lib/R/site-library/rJava/libs/rJava.so':
  libjvm.so: cannot open shared object file: No such file or directory
Error: package or namespace load failed for ‘rJava’

I'm on Ubuntu 14.04 64 bit and am using R version 3.1.0 (2014-04-10) -- "Spring Dance"

UPDATE: Actually this is not specific to OpenJDK, I just tried oracle java 8 and got the same result. Also I found this workaround here which I am reluctant to use since it is indeed a workaround and doesn't really explain why it's necessary. The package system should have handled this in my opinion. Seems like libjvm.so is the problem and I have it located here

/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/jamvm/libjvm.so
/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/server/libjvm.so
/usr/lib/jvm/java-7-oracle/jre/lib/amd64/server/libjvm.so

and for some reason rJava fails to find them despite updating with sudo R CMD javareconf.

UPDATE 2: The plot thickens: If I run R as sudo it works.

Thankful for pointers.

Answer 1

you can solve this problem by opening rstudio in super user like

sudo rstudio

then inside R run

install.packages('rJava')