RWeka installation error: “Need at least Java version 1.7/7.0”, but I have 1.8

Question

I am trying to install RWeka package in R 3.3.0:

* installing *source* package ‘RWeka’ ...
** package ‘RWeka’ successfully unpacked and MD5 sums checked
Need at least Java version 1.7/7.0.
ERROR: configuration failed for package ‘RWeka’

However, I have Java 1.8, so it should be fine. Curiously, I was able to install RWekajars which should have similar Java dependencies.

To confirm Java on the command line:

$ java -version
openjdk version "1.8.0_121"

Then in R:

> library(rJava)
> .jinit()
> .jcall("java/lang/System", "S", "getProperty", "java.runtime.version") 
[1] "1.8.0_121-b13"

Why does RWeka think I do not meet the Java requirement?

Answer 1

I looked at $LD_LIBRARY_PATH/R/etc/Makeconf and JAVA_HOME there was set to 1.6. Therefore, R thinks that Java is 1.6 even though 1.8 is loaded.

This can be fixed by running:

R CMD javareconf

That requires root privileges.