How to hide public classes in library Jar using ProGuard (or any other way)?

Question

I want to build a library, but I don't want some classes to be exposed to the developer, but I do want them to be exposed to my library code and tests easily.

Is there a way to hide specific public classes using ProGuard or in any other way (like the @hide notation used in Android SDK)?

Answer 1

the whole point of obfuscatin is that it hides the method for people on the outside, but references inside the library are updated. Typically, you'll have a

void myMethodWithAVeryExplicitName() {
    // Do Stuff
}

void otherMethod() {
    // Call the first method
    myMethodWithAVeryExplicitName();
}

It will be obfuscated as :

void a() {
    // Do Stuff
}

void b() {
    // Call the first method
    a();
}

Then Proguard has a lot of options for obfuscating or keeping public classes, classes that extend specific classes, members ...

Answer 2

Maybe a facade ( http://en.wikipedia.org/wiki/Facade_pattern ) would help. The purpose of this pattern is similar with your problem. It offers a reduced to the outside world while it keeps all the bells and whistles inside the library.