Obfuscation of protected class members - good/bad?

Question

Hi,
there was a post regarding de-obfuscation, so i thought I�d ask a philosophical question and your opinion on another related problem.
I�ve seen an API for one product with protected methods and viriables documented in the javadoc. However, when trying to subclass API classes, it turns out that these protected methods have been obfuscated, often making meaningful subclassing impossible.
What do people think about such things? How do such practices stand from the OOP point of view? I would guess this is a bad violation...
Philip

Answer 1

After all, I don't understand the point of
obfuscation. The JVM was designed in a way that
de-obfuscators are always on the strong side -- The
JVM has to ensure even for obfuscated programs that
they don't do any damage to your system, so it must
(kind of) de-obfuscate them.An example of obfuscation:
before:
if (KeyValidator.validate(userKey, userName)) { 
  runApplication();
} else {
  displayMessage("Your key is invalid, please purchace a key...");
  System.exit(0);
}If you dowloaded a demo, decompiled it and looked at the code it would be easy to hack it to make it work without a key... so the creators of the code obfuscate it. This renames methods and objects, replaces strings with encryped strings transformed my a method, and throws in meaningless code:
after:
if (a(A.a).b(c, C){
  x();
} else if (z.c(e.rr(0x03<<2) {
} else{
  z(xlp("[2039rj[0q4q[q03q4hr[q09f[0f9h[0qwe9hf[q0we9r8[0q23f[02934");
  System.exit(0);
}now that this garbage is in the middle of 1.5M of similar source code, it's no longer obvious what this does.
Similarly, obfuscated code can protect proprietary algorithms.