Java Mobile Game Ripping Assistance Needed

Hello Java mobile game rippers. I need help with ripping images, audio, etc from various game titles:

-Alien Quarantine (Space Horror), Gameloft Ltd
-Gang Threat Ardor, E7play Ltd
-Gangstar 1: Crime City, Gameloft Ltd
-Gangstar 2: Kings of L.A., Gameloft Ltd
-Gangstar 3: Miami Vindication, Gameloft Ltd
-Gangstar 4: Rio, City of Saints, Gameloft Ltd

The problem I'm having is that there are blank files and .class files inside of the .jars but I'm not sure what I'm looking for. I think .class is just the scripts, but I'm not sure what the files with the blank filetype are.
Here is a link to the files in question.
If you happen to know how to get into these files or what they are, please let me know via pm.