Not able to install rJava in R (ubuntu 18.04)

On my clean installation of Ubuntu 18.04 LTS I did the following

sudo apt-get install r-base-dev default-jdk

(so I have R 3.4 from official repository).

Then in R or in RStudio 1.1.456 session:

install.packages('rJava')

and it ended with

* DONE (rJava)

---

Note: I'm using default OpenJDK 11 from Bionic repository -

$ update-java-alternatives -l
java-1.11.0-openjdk-amd64      1101      /usr/lib/jvm/java-1.11.0-openjdk-amd64

In my case, I also had to use: sudo R CMD javareconf, to make it work.

Running Ubuntu 18.04 64-bit, R 3.60, and RStudio 1.2.1335.

In my case, I had to do the following:

1. (Temporarily) disable Oracle Java 8 by renaming jdk.csh and jdk.sh to jdk.csh.old and jdk.sh.old (in etc/profile.d).

2. Install java-11-openjdk.

3. Add JAVA_HOME="/usr/lib/jvm/java-11-openjdk" to /etc/environment.

4. Run "sudo update-alternatives --config java" and select "/usr/lib/jvm/java-11-openjdk-amd64.bin/java".

5. Run "sudo R CMD javareconf".

6. Logout/login.

7. Open RStudio and install rJava.

rJava then installed with no errors.