error: unable to load installed packages just now

For Linux(Ubuntu) users: If you have oracle-java (7/8) installed. It'll be at this location /usr/lib/jvm and sudo access is required.

Create the file /etc/ld.so.conf.d/java.conf with the following entries:

/usr/lib/jvm/java-8-oracle/jre/lib/amd64/usr/lib/jvm/java-8-oracle/jre/lib/amd64/server

(Replace java-8-oracle with java-7-oracle depending on your java version)

Then:

sudo ldconfig

Restart RStudio and then install the rJava package.

OR

Also an alternative method is to export LD_LIBRARY_PATH with the value of Java library path obtained from the command R CMD javareconf -e and run install.packages

I got similar issue and was able to resolve it by running

R CMD javareconf -e

Output of the R CMD javareconf -e

Java interpreter : /export/apps/jdk/JDK-1_6_0_27/jre/bin/javaJava version     : 1.6.0_27Java home path   : /export/apps/jdk/JDK-1_6_0_27Java compiler    : /export/apps/jdk/JDK-1_6_0_27/bin/javacJava headers gen.: /export/apps/jdk/JDK-1_6_0_27/bin/javahJava archive tool: /export/apps/jdk/JDK-1_6_0_27/bin/jarJava library path: /export/apps/jdk/JDK-1_6_0_27/jre/lib/amd64/server:/export/apps/jdk/JDK-1_6_0_27/jre/lib/amd64:/export/apps/jdk/JDK-1_6_0_27/jre/../lib/amd64:/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/libJNI linker flags : -L/export/apps/jdk/JDK-1_6_0_27/jre/lib/amd64/server -L/export/apps/jdk/JDK-1_6_0_27/jre/lib/amd64 -L/export/apps/jdk/JDK-1_6_0_27/jre/../lib/amd64 -L/usr/java/packages/lib/amd64 -L/usr/lib64 -L/lib64 -L/lib -L/usr/lib -ljvmJNI cpp flags    : -I/export/apps/jdk/JDK-1_6_0_27/include -I/export/apps/jdk/JDK-1_6_0_27/include/linuxThe following Java variables have been exported:JAVA_HOME JAVA JAVAC JAVAH JAR JAVA_LIBS JAVA_CPPFLAGS JAVA_LD_LIBRARY_PATHRunning: /bin/bash

After setting LD_LIBRARY_PATH to the same value as JAVA_LD_LIBRARY_PATH as shown in the output above. I was able to install rj.

export LD_LIBRARY_PATH=/export/apps/jdk/JDK-1_6_0_27/jre/lib/amd64/server:/export/apps/jdk/JDK-1_6_0_27/jre/lib/amd64:/export/apps/jdk/JDK-1_6_0_27/jre/../lib/amd64:/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib

Run R and then install rj by

install.packages(c("rj", "rj.gd"), repos="http://download.walware.de/rj-1.1")

I found the solution:

export LD_LIBRARY_PATH=/usr/lib/jvm/java-7-oracle/lib/amd64:/usr/lib/jvm/java-7-oracle/jre/lib/amd64/server

then

sudo R CMD javareconf

Note: The path (java-7-oracle) needs to be updated based on your Java installation.