Guava: Google Core Libraries for Java 32.1.2-jre · com.google.common.util.concurrent.SettableFuture

A 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.

Access	Constructor and Description
private	SettableFuture()

Method Summary

Modifier and Type	Method and Description
public static <V extends @Nullable Object> SettableFuture<V>	create() Creates a new `SettableFuture` that can be completed or cancelled by a later method call.
public boolean	set(V the value to be used as the result value) Overrides com.google.common.util.concurrent.AbstractFuture.set. Sets the result of this `Future` unless this `Future` has already been cancelled or set (including set asynchronously).
public boolean	setException(Throwable the exception to be used as the failed result throwable) Overrides com.google.common.util.concurrent.AbstractFuture.setException. Sets the failed result of this `Future` unless this `Future` has already been cancelled or set (including set asynchronously).
public boolean	setFuture(ListenableFuture<? extends V> the future to delegate to future) Overrides com.google.common.util.concurrent.AbstractFuture.setFuture. 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).

Inherited from com.google.common.util.concurrent.AbstractFuture.TrustedFuture:: addListener cancel get get isCancelled isDone

Constructor Detail

SettableFuture	back to summary
private SettableFuture()

Method Detail

create	back to summary
public static <V extends @Nullable Object> SettableFuture<V> create() Creates a new `SettableFuture` that can be completed or cancelled by a later method call.

set back to summary

set	back to summary
public boolean set(V value) Overrides com.google.common.util.concurrent.AbstractFuture.set. Doc from com.google.common.util.concurrent.AbstractFuture.set. Sets the result of this `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 `cancel`. Beware of completing a future while holding a lock. Its listeners may do slow work or acquire other locks, risking deadlocks. Parameters value:V the value to be used as the result Returns:boolean true if the attempt was accepted, completing the `Future` Annotations @CanIgnoreReturnValue @Override

public boolean set(V value)

Overrides com.google.common.util.concurrent.AbstractFuture.set.

Doc from com.google.common.util.concurrent.AbstractFuture.set.

Sets the result of this 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 cancel.

Beware of completing a future while holding a lock. Its listeners may do slow work or acquire other locks, risking deadlocks.

Parameters

value:V: the value to be used as the result

Returns:boolean

true if the attempt was accepted, completing the Future

Annotations

@CanIgnoreReturnValue
@Override

setException back to summary

setException	back to summary
public boolean setException(Throwable throwable) Overrides com.google.common.util.concurrent.AbstractFuture.setException. Doc from com.google.common.util.concurrent.AbstractFuture.setException. Sets the failed result of this `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 `cancel`. Beware of completing a future while holding a lock. Its listeners may do slow work or acquire other locks, risking deadlocks. Parameters throwable:Throwable the exception to be used as the failed result Returns:boolean true if the attempt was accepted, completing the `Future` Annotations @CanIgnoreReturnValue @Override

public boolean setException(Throwable throwable)

Overrides com.google.common.util.concurrent.AbstractFuture.setException.

Doc from com.google.common.util.concurrent.AbstractFuture.setException.

Sets the failed result of this 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 cancel.

Beware of completing a future while holding a lock. Its listeners may do slow work or acquire other locks, risking deadlocks.

Parameters

throwable:Throwable: the exception to be used as the failed result

Returns:boolean

true if the attempt was accepted, completing the Future

Annotations

@CanIgnoreReturnValue
@Override

setFuture back to summary

setFuture	back to summary
public boolean setFuture(ListenableFuture<? extends V> future) Overrides com.google.common.util.concurrent.AbstractFuture.setFuture. Doc from com.google.common.util.concurrent.AbstractFuture.setFuture. 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). 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 `cancel`. 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 `interruptTask` method, and the `wasInterrupted` method will not return `true`. Beware of completing a future while holding a lock. Its listeners may do slow work or acquire other locks, risking deadlocks. Parameters future:ListenableFuture<? extends V> the future to delegate to Returns:boolean true if the attempt was accepted, indicating that the `Future` was not previously cancelled or set. Annotations @CanIgnoreReturnValue @Override

public boolean setFuture(ListenableFuture<? extends V> future)

Overrides com.google.common.util.concurrent.AbstractFuture.setFuture.

Doc from com.google.common.util.concurrent.AbstractFuture.setFuture.

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).

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 cancel.

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 interruptTask method, and the wasInterrupted method will not return true.

Beware of completing a future while holding a lock. Its listeners may do slow work or acquire other locks, risking deadlocks.

Parameters

future:ListenableFuture<? extends V>: the future to delegate to

Returns:boolean

true if the attempt was accepted, indicating that the Future was not previously cancelled or set.

Annotations

@CanIgnoreReturnValue
@Override

public final Class SettableFuture<V extends @Nullable Object>

Constructor Summary

Method Summary

Constructor Detail

Method Detail