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.

Sets the result of this Future unless this Future has already been cancelled or set (including set asynchronously ).

Sets the failed result of this Future unless this Future has already been cancelled or set (including set asynchronously ).

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).

Description copied from class: AbstractFuture

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 AbstractFuture.cancel(boolean) .

public boolean setException(Throwable throwable)

Description copied from class: AbstractFuture

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 AbstractFuture.cancel(boolean) .

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

Description copied from class: AbstractFuture

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 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 .

Description copied from class: AbstractFuture

public final void addListener(Runnable listener,
                              Executor executor)

Description copied from class: AbstractFuture

Registers a listener to be run on the given executor. The listener will run when the Future 's computation is complete or, if the computation is already complete, immediately.

There is no guaranteed ordering of execution of listeners, but any listener added through this method is guaranteed to be called once the computation is complete.

Exceptions thrown by a listener will be propagated up to the executor. Any exception thrown during Executor.execute (e.g., a RejectedExecutionException or an exception thrown by direct execution ) will be caught and logged.

Note: For fast, lightweight listeners that would be safe to execute in any thread, consider MoreExecutors.directExecutor() . Otherwise, avoid it. Heavyweight directExecutor listeners can cause problems, and these problems can be difficult to reproduce because they depend on timing. For example:

The listener may be executed by the caller of addListener . That caller may be a UI thread or other latency-sensitive thread. This can harm UI responsiveness.

The listener may be executed by the thread that completes this Future . That thread may be an internal system thread such as an RPC network thread. Blocking that thread may stall progress of the whole system. It may even cause a deadlock.

The listener may delay other listeners, even listeners that are not themselves directExecutor listeners.

This is the most general listener interface. For common operations performed using listeners, see Futures . For a simplified but general listener interface, see addCallback() .

Memory consistency effects: Actions in a thread prior to adding a listener happen-before its execution begins, perhaps in another thread.

public final boolean cancel(boolean mayInterruptIfRunning)

Description copied from class: AbstractFuture