Building Problem

Hi,

My name is Nabil, a software engineering student at Polytechnique Montreal
in Canada. I am interested in participating in GSoC this year, particularly
with LIbreOffice, so, I'm new here in the world of contribution to open
source projects. I started reading on how to apply and how to get involved
in the community and started working on that. Therefore, I am now at the
stage of building LIbreOffice from source in order to start doing some
EasyHacks, but I'm having some troubles while executing the command
(./autogen.sh). I followed exactly the steps mentionned in this page, and
the command gives me the 3 foolowing warnings:

   -   * WARNING : JAVA_HOME was not explicitly informed with
   --with-jdk-home. the configure script
   -   * WARNING : attempted to find JAVA_HOME automatically, but
   apparently it failed
   -   * WARNING : in case JAVA_HOME is incorrectly set, some projects will
   not be built correctly

I spent some time trying to solve the problem by looking on the internet,
and have tried installing Java and setting $JAVA_HOME to the right
directory (/usr/bin/jvm/java-11-oracle), but this didn't work. I also tried
to look for the source of the problem and went through the configure.ac
file, and found the part of the script that generates the 3 warnings
together but still haven't figured out a way to solve it. Would you please
help get through this issue ?

Thank you!

Best regards,
Nabil Dabouz