[OpenJDK 2D-Dev] JDK-8153732 Add refresh prossibility for known printers

[Patrick Reinhart]

Hi everybody,

Now that the JDK 9 is out and the access for printing internal classes
will go away, our currently used work around to refresh the printers
known to the system will be no longer working.

In our case a reboot of our server is very difficult due the fact that
our customers work 24x7. So we would need to attach/detach printers
during a running system. The windows server, where we run our software
has those printers attached as network printers and such a change is not
recognised buy the current printing API.

It would be preferable to somehow signal that an printer change has been
taken place and the known printers to the system has to be refreshed on
the PrintServiceLookup class.

I know, that there are at least two questions around that:


How to handle an method call, that take a long time to complete?
- A possible way would be to pass some reference to an Executor for the
action being run within

What should be done in order such a method is invoked too many times?
- As this method is not be needed to be called a lot, I do not think
that this should be a problem. But if it would be done via an given
Executor, the caller would be responsible to execute

Cheers

Patrick