| Interface | Description | 
|---|---|
| CallableResultHandler<T> | 
 Used by  
AsynchronousCallableCompletionService to specify a
 callback class, whose methods are called with the result (or 
 exception) of the Callable submitted to the service. | 
| Class | Description | 
|---|---|
| AsynchronousCallableCompletionService<T> | 
 Wraps a  
CompletionService and provides an abstraction for
 submitting a set of Callables, along with a single callback class, CallableResultHandler,
 for processing the result/exception of every Callable. |