If the system property policy.provider is set then the Policy class attempts to load the provider via the boot loader and if that fails, attempts the extension loader. The implementation needs to be re-examined to see how this should work in JDK 9 and modules.

For starters, the extension mechanism is removed so there isn't a way for 3rd party policy providers to be loaded via the current mechanism. Is there any reason why the current mechanism can't always use the system class loader as the initiating loader? If the loader isn't null then the code could install the bootstrap provider before instantiating the configured policy provider.

It would also be useful if java.security.Policy should specify how it locates the configured provider, I was unable to find anything on this in the javadoc.

Finally, Policy will need to be examined to see if, or how, it should work when then policy provider is in a module.


A thread discussing this topic is here:
http://mail.openjdk.java.net/pipermail/jigsaw-dev/2015-March/004260.html