from: http://www.mjt.me.uk/posts/getting-jd-gui-to-work-on-ubuntu-13.10/

So you’ve just downloaded the latest versionof jd-gui for linux but itdoesn’t start.

TLDR:

sudo apt-get install libgtk2.0-0:i386 libxxf86vm1:i386libsm6:i386 lib32stdc++6

More details:

Here’s the process I went through:

$ ./jd-gui 
./jd-gui: error while loading shared libraries: libgtk-x11-2.0.so.0: cannot open shared object file: No such file or directory 

$ sudo apt-get install libgtk2.0-0:i386 

$ ./jd-gui 
./jd-gui: error while loading shared libraries: libXxf86vm.so.1: cannot open shared object file: No such file or directory 

$ sudo apt-get install libxxf86vm1:i386 

$ ./jd-gui 
./jd-gui: error while loading shared libraries: libSM.so.6: cannot open shared object file: No such file or directory 

$ sudo apt-get install libsm6:i386 

$ ./jd-gui 
./jd-gui: error while loading shared libraries: libstdc++.so.6: cannot open shared object file: No such file or directory 

$ sudo apt-get install lib32stdc++6 

$ ./jd-gui 

Gtk-Message: Failed to load module "overlay-scrollbar"
Gtk-Message: Failed to load module "unity-gtk-module"
(jd-gui:4746): Gtk-WARNING **: Unable to locate theme engine in module_path: "murrine",
...And it works!

Happy decompiling!