Expose native error codes and strings on private Exceptions?

[Michael StJohns]

Hi -

As Java has become more modularized and locked down, I've lost some easy 
access to critical information in two places - PCSC and PKCS11.  I 
haven't gone back to dealing with JDBC recently, but I think I might 
have the same problem there.

To give you an example, java.smartcardio.CardException almost always 
hassun.security.smartcardio.PCSCException as a "cause", and 
PCSCException usually has a useful error code such as 
SCARD_E_NO_READERS_AVAILABLE.  The problem is that I can't coerce the 
Throwable from getCause() to PCSCException post JDK8 without going 
through a number of hoops to open up various modules. Parsing the return 
from getMessage() on the cause sort of works for PCSC stuf, but could 
break in weird ways since those formats aren't specified.

Similar stories exist on the PKCS11 side of things.

I'm wondering if it would make sense to create a public interface that 
these closed off implementation or factory classes could implement that 
would allow for the retrieval of the native codes and messages without 
workarounds?  E.g.  something like:


package java.lang; // or maybe java.util?

public interface NativeException {

    public Long getNativeErrorCode(); // Return null if not supported

    public String getNativeErrorMessage(); // Return null if not supported

}


Obviously, this is more general than just the security stuff, but that's 
where I've run into the related problems.

Thanks - Mike