“unable to load shared object” when loading the rJava library

Question

I apologize in advance for my bad english, i hope that someone can help me. I have to load an Excel file .xlsx on R, but:

library(xlsx)

Answer 1

In Ubuntu 16.04 I did the following trick in RStudio:

Sys.setenv('JAVA_HOME' = '/usr/lib/jvm/java-8-oracle/jre')

Surprisingly, but

Sys.setenv('JAVA_HOME' = '/usr/lib/jvm/java-8-oracle/')

didn't work for me.