RFR: 8216363: NullPointerException in java.util.logging.Handler#isLoggable

[Daniel Fuchs]

Hi Mandy,

On 14/02/19 20:20, Mandy Chung wrote:
> Fixing the implementation of Handler::isLoggable to return false
> if null to match the specification seems similar risk to changing
> the spec.  What do you think?

How so? I mean - if no line of code is changed, then surely we can't
break existing code? But on second thought I believe I may
have made the wrong choice her. See below...


> In addition, logging tends to be gracious as it's a
> cross-cutting concern and not to disturb the application runtime
> until it's a runtime issue.  So I think isLoggable accepting null
> may be by design.

I agree that returning false would be a much better implementation
than throwing NPE. StreamHandler already does that. The only
concrete implementation (in the JDK) of Handler that doesn't
return false is the memory handler.

> Handler.publish(LogRecord) specifies to ignore null record and
> the implementation calls Handler.isLoggable(record). If the spec
> is changed to throw NPE, Handler::publish will need to change
> too.  This impacts all APIs that accept null LogRecord while
> assuming isLoggable(null) returns false.

That is a good point.

> I think normal logging purpose would pass non-null records
> otherwise this issue should have been reported long ago.

Well... That and the fact that FileHandler, ConsoleHandler,
and friends are all StreamHandler (and return false).

Maybe you're right - and changing the implementation
is the right thing to do.

Let me redo my fix and see if the JCK complains.

Thanks for the feedback!

best regards,

-- daniel