Now what was it?  "Avada Kedavra" .. something ? 

Well JInput downloaded and tested with these handy step by step guide creates an EVIL ELF !!!

java.lang.UnsatisfiedLinkError: /home/pi/jinput/dist/libjinput-linux64.so: /home/pi/jinput/dist/libjinput-linux64.so: wrong ELF class: ELFCLASS64 (Pos

That's not what we want...  But it's open source Yay !

We'll need to Use the Source, Luke

To get the source and build it we'll need gcc & subversion at the least, run these apt-get's to get whatcha need.

sudo apt-get update
sudo apt-get install pkg-config git subversion make gcc g++ python binutils-gold ant

Then to check out the code:

svn co https://svn.java.net/svn/jinput~svn/trunk

as I saw the checkout fly by .. I saw these files...

A    trunk/plugins/linux/src/native
A    trunk/plugins/linux/src/native/build.xml
A    trunk/plugins/linux/src/native/net_java_games_input_LinuxJoystickDevice.c
A    trunk/plugins/linux/src/native/net_java_games_input_LinuxEventDevice.c
A    trunk/plugins/linux/src/native/getDefinitions
 
Looks promising - and since it has a build.xml I'm guessing they have ant spawn off a gcc build.
Saw a README but that would be cheating !
 
Compile first and ask questions later !