They cannot run it unless they are a valid and authentic user or unless they steal someone’s account (or if you put a back door in your code – which you should not). If your communications are secure and cannot be spoofed then it doesn’t really matter if the hacker sees the source code. Packet sniffing is one of the first tools of a good hacker. In this case the communications method must be secure (encrypted and authenticated) and as close to impossible to spoof as possible. This is not high stakes IP.įorth, what is high stakes IP is how data is transmitted between the client to the server. I mean sure, it does take time and effort to do it, but we are basically talking about presenting input fields and buttons to the user. Third, since the only Java code runnning on the client is presentation logic the code should not be very valuable in terms of IP. If the server is not sercure you have much bigger problems than someone decompiling the Java byte code. All business logic and data access should be on the server and the server should be secure from prying eyes. Second, the only Java code that should be on the client machine should be presentation logic.

Misleading code and bad class names do not make the code better – and, as I said, cannot stop a determined hacker. Because of this controlled and safe code, about the only options available are to rename classes and methods or to introduce misleading code that is essentially ‘no ops’ but that may confuse the decompiler. The fact that Java can detect safe code (unlike say Win32 binary code) come from the fact that Java has very controlled access to resources like memory and IO and such. But it is not that hard, really, I mean Java checks all byte code to be sure it is safe before it runs the code. Someone determined to break in will find a way – ultimately all code will depend on the core Java library and there is no way to hide that – from there it is just a matter of spending hours of decoding the byte code. First, there is no way you can make Java impossible to decompile – but you can make it very difficult.

Open source java decompiler