Using Security manager to prevent public method access

I had once come across a post that said that we can use the 开发者_开发百科SecurityManager to restrict certain classes from calling a public method of another class. How do we do that?

You could have at least linked to the answer, and then said more clearly, what you don't understand. So, I will link for you to my answer to a similar question from yesterday.

If something still is not clear, comment on this answer.

Perhaps they are thinking of hiding packages hierarchies from classes loaded by other class loaded through the package.access security property. See Guidelines 1-1a of the Secure Coding Guidelines for the Java Programming Language, Version 3.0. Other than that, if a class cannot see a ClassLoader (by any means!) then they will not be able to interact with classes of that class loader.