Installing rJava on Ubuntu

Installing the rJava package on Ubuntu is not quite as simple as most other R packages. Some quick notes on how to do it.

  1. Update the repository listings.
    sudo apt update -y
  2. Install the Java Runtime Environment (JRE) and Java Development Kit (JDK).
    sudo apt install -y openjdk-8-jdk openjdk-8-jre
  3. Update where R expects to find various Java files.
    sudo R CMD javareconf
    If you get an error about jni.h not being found, then try this:
    sudo R CMD javareconf JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64/
  4. Install the package.
    > install.packages("rJava")
  5. If you have a RStudio session open, then exit and restart it. This is important (a running RStudio session will not pick up these changes!).