[jsr294-modularity-eg] Static compilation

[Michal Cierniak]

On 5/2/07, Glyn Normington <glyn_normington at uk.ibm.com> wrote:
> "Michal Cierniak" <cierniak at google.com> wrote on 01/05/2007 18:33:07:
>
>  > We haven't talked about such details but my
>  > assumption was that it should be possible to dynamically load a class
>  > that extends any non-final class including those classes that are not
>  > exported.
>
> My expectation is different, as you may have guessed.

Glyn,

I think that your expectation is completely reasonable but I think
that we would need more mechanisms to enforce this problem because the
JSR-277 APIs as presented in the EDR allow you to arrive at the
problem described by me.  Here's some pseudocode that shows my
scenario (it's pseudo in the sense that I didn't look up carefully the
APIs or tried to compile it, so that are probably some typos there):

class A {
  // class is in a module M and is not exported
  public void F() {
     ClassLoader cl = A.class.getClassLoader();  // M's classloader
     byte[] b = getBytes();  // bytes defining a class that subclasses A
     Class b = cl.defineClass("B", b, 0, b.length);
  }
  byte[] getBytes() { ...}
}

In this example, I use A's classloader to create class B which is a
subclass of A.

Dealing with classloaders is always tricky, so I may be missing
something here.  What do you think about my example?

Michal