How to make java code illegible?

[iron_man]

Greeting,

How can I avoid the power of decompiler? I don't use double in my game, if somebody else wants to get the code, a simplest decompiler can do the job in one second. If I want to sell my game, it shoudn't be an open source.

I note some commercial game, even the name of class is a, b, c, d..., I guess in the code, it's seam thing.

Which tool I can use to do it?

Best regard.

[petrib]

The keyword to search for (here or using your favourite Internet search engine) is "obfuscator".

If you want something more than that, switch to C++ and native code, instead of Java.

[iron_man]

cool, thanks!!

[wzjimmy]

you can use the ProGuard

[Redwid]

you can use the ProGuard

or RetroGuard

[pksm]

ProGuard will solve ur problem easily.

[srinivasvurrinkala]

yes use the obfuscators as well dont write whole logic in the main MIDLet class
since thats visible

[adilb]

Hi,
As suggested above by most of them u definetly can use any obfuscator in the market available like proguard,retroguard or any othe rif u like ..all these obfuscators what they do is try and change the function names variable names which are like a_ , abyte0 etc dependin upon there own algoritms...however since there are various types of obfuscators available and each one uses a differnt technique to do this ..it nearly impossible to get back the java code from class files using decompile techniques ...morover u may obsere that the code even won 't compile sometimes after u have decompiled it.. another thing is that decompiler tools like DJ java decompiler what they do is make an approximation of code in the sense most of the time we will se switch in place of the ifelse blocks we had added ...so stop worrying about it and enjoy ur development..however there are always chances that they might be able to figure out some logic from ur code afer long hours of analysis of the decompiled code..thats actually unavoidable

[alfio.locastro]

ProGuard, absolutly.

but... remember you have to use carefully classforname calls, and sometimes (a few time in my developer career), if your code is too complex (recursive nidifications, long 'if' blocks etc), ProGuard is unable to obfuscate it.

Alfio

Lead Programmer
http://www.javartgames.com