Getting RStudio to work with RWeka and the previous java 1.8 problem

So, from the previous post, installing Java 1.6 and recompiling rJava is enough to get everything working from a terminal window. But, if you start up RStudio and try to use RWeka (or other libraries using JNI, probably) you'll see an error message similar to:

Error : .onLoad failed in loadNamespace() for 'rJava', details:
  call: dyn.load(file, DLLpath = DLLpath, ...)
  error: unable to load shared object '/usr/local/Cellar/r/3.2.0_1/R.framework/Versions/3.2/Resources/library/rJava/libs/rJava.so':
  dlopen(/usr/local/Cellar/r/3.2.0_1/R.framework/Versions/3.2/Resources/library/rJava/libs/rJava.so, 6): Library not loaded: @rpath/libjvm.dylib
  Referenced from: /usr/local/Cellar/r/3.2.0_1/R.framework/Versions/3.2/Resources/library/rJava/libs/rJava.so
  Reason: image not found
Error: package or namespace load failed for ‘RWeka’

A workaround is to start RStudio from a terminal window by running the following line:

LD_LIBRARY_PATH=$(/usr/libexec/java_home)/jre/lib/server: open -a RStudio

Getting various R packages to work with Java 1.8 and rJava on OSX

If you attempt to install various R packages (e.g. RWeka) on OSX using a Java 1.8 runtime, you're likely to run into the following error message (even though you have a perfectly good installation of Java):

"No Java runtime present, requesting install.
ERROR: loading failed"

There are a ton of threads out there about this problem, but it seems to boil down to this unclosed (and untouched since 2014-01) JDK issue -> https://bugs.openjdk.java.net/browse/JDK-7131356

The "solution" can be found on the last comment on this rJava github issue: https://github.com/s-u/rJava/issues/37

1. install JDK 1.6 from Apple (http://support.apple.com/kb/DL1572)
2. open a new terminal window and make sure you're still using 1.8 - "java -version"
3. run "sudo R CMD javareconf -n" from a terminal window
4. start up R and install rJava again from source - install.packages("rJava", type="source")