About Question enthuware.ocpjp.v7.2.1688 :

[krohani]

Paul - I have a question about shutdownNow() method in ExecutorService. The API (and your answer) shows that it returns a list of runnable tasks that were awaiting execution. Here is my question...

1. You can submit both runnables and callables to the executorservice and I don't believe they inherit from each other so what happens to the callables that were awaiting execution when the shutdownNow is called. They don't get returned back in this list, correct?

[admin]

The API doesn't say anything about that but I believe it is possible for the method to return both by wrapping a Callable into a Runnable. You would have to look into the source code of some concrete ExecutorService to see what it actually does.

HTH,
Paul.