Interface CheckedFuture<V,X extends Exception>
- All Superinterfaces:
Future<V>
,ListenableFuture<V>
- All Known Implementing Classes:
AbstractCheckedFuture
,ForwardingCheckedFuture
,ForwardingCheckedFuture.SimpleForwardingCheckedFuture
CheckedFuture
is a ListenableFuture
that includes versions of the get
methods that can throw a checked exception. This makes it easier to create a future that executes
logic which can throw an exception.
Warning: We recommend against using CheckedFuture
in new projects.
CheckedFuture
is difficult to build libraries atop. CheckedFuture
ports of methods like
Futures.transformAsync(com.google.common.util.concurrent.ListenableFuture<I>, com.google.common.util.concurrent.AsyncFunction<? super I, ? extends O>)
have historically had bugs, and some of these bugs are necessary,
unavoidable consequences of the CheckedFuture
API. Additionally, CheckedFuture
encourages users to take exceptions from one thread and rethrow them in another, producing
confusing stack traces.
A common implementation is Futures.immediateCheckedFuture(V)
.
Implementations of this interface must adapt the exceptions thrown by Future#get()
:
CancellationException
, ExecutionException
and InterruptedException
into
the type specified by the X
type parameter.
This interface also extends the ListenableFuture interface to allow listeners to be added.
This allows the future to be used as a normal Future
or as an asynchronous callback
mechanism as needed. This allows multiple callbacks to be registered for a particular task, and
the future will guarantee execution of all listeners when the task completes.
For a simpler alternative to CheckedFuture, consider accessing Future values with Futures.getChecked()
.
- Since:
- 1.0
-
Nested Class Summary
Nested classes/interfaces inherited from interface java.util.concurrent.Future
Future.State
-
Method Summary
Modifier and TypeMethodDescriptionException checking version ofFuture.get()
that will translateInterruptedException
,CancellationException
andExecutionException
into application-specific exceptions.checkedGet
(long timeout, TimeUnit unit) Exception checking version ofFuture.get(long, TimeUnit)
that will translateInterruptedException
,CancellationException
andExecutionException
into application-specific exceptions.Methods inherited from interface java.util.concurrent.Future
cancel, exceptionNow, get, get, isCancelled, isDone, resultNow, state
Methods inherited from interface com.google.common.util.concurrent.ListenableFuture
addListener
-
Method Details
-
checkedGet
Exception checking version ofFuture.get()
that will translateInterruptedException
,CancellationException
andExecutionException
into application-specific exceptions.- Returns:
- the result of executing the future.
- Throws:
X
- on interruption, cancellation or execution exceptions.
-
checkedGet
Exception checking version ofFuture.get(long, TimeUnit)
that will translateInterruptedException
,CancellationException
andExecutionException
into application-specific exceptions. On timeout this method throws a normalTimeoutException
.- Returns:
- the result of executing the future.
- Throws:
TimeoutException
- if retrieving the result timed out.X
- on interruption, cancellation or execution exceptions.
-