Question

I understand that callable’s call can throw the exception to the parent method calling it which is not the case with runnable.

I wonder how because it’s a thread method and is the bottommost method of the thread stack.

Answer 1

The point of Callable is to have your exception thrown to your calling thread, for example when you get the result of a Future to which you submitted your callable.

public class CallableClass implements Callable<String> {
...
}

ExecutorService executor = new ScheduledThreadPoolExecutor(5);
Future<Integer> future = executor.submit(callable);

try {
    System.out.println(future.get());
} catch (Exception e) {
    // do something
}