What can done to secure jar files besides obfuscation?

Question

I\'m concerned about the security of Java executables. They offer little protection against decompilation. With tools like Java Decompiler even a kid can decompile the class

Answer 1

You can write all your code with in native. The reverse engineering can be done anyway. But is harder.

Ok, this is not a strictly java solution.

As nfechner said in a comment write open source application.