Re: How to let the methods of a class only can be invoked by a special package(the class not in the package)?

Andreas Leitgeb <>
25 Jan 2008 11:58:12 GMT
Jebel <> wrote:

I not understand how to do this. How can I "wrap" B's methods ?
Would you please provide some code as a example?

It was based on a wrong understanding on my side. Sorry, but
I think it doesn't apply, anyway.

The point was about your class in which you could
give a such limited interface, that noone could do anything
harmful with it, even if the wrong "user" tries...

The wrapping was just meant as a way to restrict the interface:
class B {
   // lots of public methods, some of which are potentially dangerous
   public void foo() { ... }
   public void bar() { ... }
   public void snafu() { ... }
class BWrapper {
   B wrappedB;
   BWrapper(B b) { wrappedB=b; }
   private B getB() { return wrappedB; }
   // just the really important methods:
   public void foo() { do some checks, and then: getB().foo(); }
After that, you can give all the methods of B default-access,
and no one else can use anything than foo() on B, and only through
your class BWrapper (unless they find a way to sneak code into
xx.zz or bypassing your classloader, or patching their

Also, I don't yet understand what big evil would be unleashed by
letting people just use your as they feel like.

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