@GwtCompatible public final class SettableFuture<V> extends AbstractFuture.TrustedFuture<V>
ListenableFuture
whose result can be set by a set(Object)
, setException(Throwable)
or setFuture(ListenableFuture)
call. It can also, like any
other Future
, be cancelled.
SettableFuture
is the recommended ListenableFuture
implementation when your
task cannot be implemented with ListeningExecutorService
, the various Futures
utility methods, or ListenableFutureTask
. Those APIs have less opportunity for developer
error. If your needs are more complex than SettableFuture
supports, use AbstractFuture
, which offers an extensible version of the API.
ValueFuture
)AbstractFuture.TrustedFuture<V>
Modifier | Constructor and Description |
---|---|
private |
SettableFuture() |
Modifier and Type | Method and Description |
---|---|
static <V> SettableFuture<V> |
create()
Creates a new
SettableFuture that can be completed or cancelled by a later method call. |
boolean |
set(V value)
Sets the result of this
Future unless this Future has already been cancelled or
set (including set asynchronously). |
boolean |
setException(java.lang.Throwable throwable)
Sets the failed result of this
Future unless this Future has already been
cancelled or set (including set asynchronously). |
boolean |
setFuture(ListenableFuture<? extends V> future)
Sets the result of this
Future to match the supplied input Future once the
supplied Future is done, unless this Future has already been cancelled or set
(including "set asynchronously," defined below). |
addListener, cancel, get, get, isCancelled, isDone
afterDone, interruptTask, maybePropagateCancellationTo, pendingToString, toString, trustedGetException, wasInterrupted
addCallback, catching, catchingAsync, from, transform, transformAsync, withTimeout
public static <V> SettableFuture<V> create()
SettableFuture
that can be completed or cancelled by a later method call.public boolean set(V value)
AbstractFuture
Future
unless this Future
has already been cancelled or
set (including set asynchronously). When a call to this method returns,
the Future
is guaranteed to be done only if the call was
accepted (in which case it returns true
). If it returns false
, the Future
may have previously been set asynchronously, in which case its result may not be known
yet. That result, though not yet known, cannot be overridden by a call to a set*
method, only by a call to AbstractFuture.cancel(boolean)
.set
in class AbstractFuture<V>
value
- the value to be used as the resultFuture
public boolean setException(java.lang.Throwable throwable)
AbstractFuture
Future
unless this Future
has already been
cancelled or set (including set asynchronously). When a call to this
method returns, the Future
is guaranteed to be done only if
the call was accepted (in which case it returns true
). If it returns false
, the
Future
may have previously been set asynchronously, in which case its result may not be
known yet. That result, though not yet known, cannot be overridden by a call to a set*
method, only by a call to AbstractFuture.cancel(boolean)
.setException
in class AbstractFuture<V>
throwable
- the exception to be used as the failed resultFuture
@Beta public boolean setFuture(ListenableFuture<? extends V> future)
AbstractFuture
Future
to match the supplied input Future
once the
supplied Future
is done, unless this Future
has already been cancelled or set
(including "set asynchronously," defined below).
If the supplied future is done when this method is called and the call
is accepted, then this future is guaranteed to have been completed with the supplied future by
the time this method returns. If the supplied future is not done and the call is accepted, then
the future will be set asynchronously. Note that such a result, though not yet known,
cannot be overridden by a call to a set*
method, only by a call to AbstractFuture.cancel(boolean)
.
If the call setFuture(delegate)
is accepted and this Future
is later
cancelled, cancellation will be propagated to delegate
. Additionally, any call to
setFuture
after any cancellation will propagate cancellation to the supplied Future
.
Note that, even if the supplied future is cancelled and it causes this future to complete,
it will never trigger interruption behavior. In particular, it will not cause this future to
invoke the AbstractFuture.interruptTask()
method, and the AbstractFuture.wasInterrupted()
method will not
return true
.
setFuture
in class AbstractFuture<V>
future
- the future to delegate toFuture
was not previously
cancelled or set.