Why are classes so easy to decompile
Hello guys,
I was interested in how Java actually works. So i came to the fact that you can decompile classes and get 99% correct output.
Now i compared to the C family, and i've read it is possibly too, but alot harder to do it. (Thats what i've read)
So i'm asking why java classes are so easy to decompile? Can't it be changed so the work of an author is more secure and protected to people who want to rip your source? (I'm talking then about applets)
Please do not flame as this is only a subject i discovered.
Thanks in advance,
jojo123
Edit: changed title :)
jojo123 wrote:
They can obtain the class files as it is an applet, and as far as i know i don't know any method to protect them from getting it?
So they can find out how everything works, and so they can try to cheat by sending wrong values (eg: sending 1000 coins while you only have 1)
But that is fixable server-side.If your fellow students are actively trying to attack your work by grabbing the class files, decompiling them, finding errors, and then demonstrating the errors, then they're doing you a favor. (Well, at least if they tell you what they found.) They're doing you a favor by finding bugs in your program for you. This is called "quality assurance" (aka QA) and companies pay people to do it.
The solution is to write stronger code that doesn't have those errors!
No, you can't prevent people from getting the class files for an applet. The whole point of an applet is that people download it and run it locally. If they can run it, they can decompile it. This is true of any language.
The discussion was actually why they don't update java to prevent it being so easily decompilable, but i don't really got an answer on that.It's not really so easily decompilable. As I said it's really only easier inasmuch as the object code (compiled classes) are more discrete than object code in other languages, and because there's a single virtual machine. Those are both advantages of the language (at least for certain applications, such as the ones that Java has become popular in). So that's why they don't "update java to prevent it being so easily decompilable". It would make the language worse.
Decompiling really isn't a problem.
Keep in mind that a lot of popular languages aren't compiled at all, or they're compiled only at runtime and the scripts are deployed as source code.
Don't worry about it.
Edited by: paulcw on Nov 30, 2009 11:34 AM
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