R: rJava package install failing

Question

When installing rJava using the install.packages("rJava") command I get the following error:

checking Java support in R... present:
interpreter : '/usr/bin/java'
archiver    : '/usr/bin/jar'
compiler    : '/usr/bin/javac'
header prep.: '/usr/bin/javah'
cpp flags   : '-I/usr/lib/jvm/java-6-sun-1.6.0.20/jre/../include -I/usr/lib/jvm/java-6-sun-1.6.0.20/jre/../include/linux'
java libs   : '-L/usr/lib/jvm/java-6-sun-1.6.0.20/jre/lib/amd64/server -L/usr/lib/jvm/java-6-sun-1.6.0.20/jre/lib/amd64 -L/usr/lib/jvm/java-6-sun-1.6.0.20/jre/../lib/amd64 -L -L/usr/java/packages/lib/amd64 -L/usr/lib64 -L/lib64 -L/lib -L/usr/lib -ljvm'
checking whether JNI programs can be compiled... yes
checking JNI data types... configure: error: One or more JNI types differ from the corresponding native type. You may need to use non-standard compiler flags or a different compiler in order to fix this.
ERROR: configuration failed for package ‘rJava’

I have the Java JDK installed and java -version returns the following:

$ java -version
java version "1.6.0_20"
Java(TM) SE Runtime Environment (build 1.6.0_20-b02)

When Googling around for the error I see that others are having the same issue but not finding a solution other than "install the whole JDK, not just the JRE" which I have done.

The other thing I read was to run sudo R CMD javareconf which runs quite happily with no errors.

Any ideas what my problem is?

[[EDIT]] It's been a few months since I had this problem. I had initially solved this by editing my Java paths, as illustrated in the answer I posted below. I recently ran into the same issue on a new Ubuntu install. I tried Dirk's recommendation to use apt-get to install the rJava package. It worked perfectly. What I failed to appreciate initially is that installing packages using the Ubuntu apt-get method is fundamentally different than just loading the same package using install.packages() inside of R. The Ubuntu packages solve some issues which I didn't realize or appreciate.

Answer 1

Turns out my problem was an issue with my JAVA_HOME environment variable. Yes, shocking I know. My initial setting for PATH and JAVA_HOME looked like this:

export JAVA_HOME=/usr/lib/jvm/java-6-sun
export PATH=$PATH:$JAVA_HOME/bin

And I added /jre so it now looks like this:

export JAVA_HOME=/usr/lib/jvm/java-6-sun/jre
export PATH=$PATH:$JAVA_HOME/bin

Everything in Java seemed to work fine without the /jre but rJava would not. Odd.

Answer 2

Wouldn't

apt-get install r-cran-rjava

have been easier? You could have asked me at useR! :)

Answer 3

I am 'the next guy' whose time you saved JDLong. Funny that I run into the same bunch of expert aRrr'ers, Dirk, Drew and JDLong. Gracias!