get,”Because the call to Future.__() will block, you must do one of the following: (1) Submit all your work to the ExecutorService before calling any Future._() methods (2) Be prepared to wait for that Future to obtain the result (3) Use a non-blocking method such as Future.isDone() before calling Future.get() or use Future.get(long timeout, TimeUnit unit)

get,”Because the call to Future.__() will block, you must do one of the following: (1) Submit all your work to the ExecutorService before calling any Future._() methods (2) Be prepared to wait for that Future to obtain the result (3) Use a non-blocking method such as Future.isDone() before calling Future.get() or use Future.get(long timeout, TimeUnit unit)

which will throw a TimeoutException if the result is not available within a given duration”