To run java app on android and Converting Java (J2ME) Applications To Android .apk Format Can Be Done Easily Android .apk Files Or Applications And What They Consist Of When Google started creating Android applications, they use an extension which is the .apk format, now this .apk format is just disguising extension just for Android but its nothing, Android .apk files are zipped archives files but saved in a different extension, you don't believe me? Yea I did not believe too until I tried it myself and confirmed it.
You too can try and confirm it, get an Android .apk format application on a computer, then rename the extension to .zip format and see how to changes to a zipped file.
When you open the zipped file it consist of a file named classes.dex which is the main file of the application consisting of all the java files, now you hear java files; yes java makeup and Android application. Now this classes.dex files can also be disassembled, this can be done through some process because the java files in the classes.dex files are compiled differently.
What You Will Need To Disassemble the classes.dex File To disassemble the classes.dex you will need to get this two files " - Dex2Jar from http://
code.google.com/p/ dex2jar/ - A regular Java decompiler, such as JD from http://java.decompiler.free.fr
Unzip the Dex2Jar In the Dex2jar directory, paste the class