Class ListenableFutureTask<V extends @Nullable Object>

java.lang.Object
java.util.concurrent.FutureTask<V>
com.google.common.util.concurrent.ListenableFutureTask<V>
All Implemented Interfaces:
ListenableFuture<V>, Runnable, Future<V>, RunnableFuture<V>
@GwtIncompatible public class ListenableFutureTask<V extends @Nullable Object> extends FutureTask<V> implements ListenableFuture<V>
A FutureTask that also implements the ListenableFuture interface. Unlike FutureTask, ListenableFutureTask does not provide an overrideable done() method. For similar functionality, call addListener(java.lang.Runnable, java.util.concurrent.Executor).

Few users should use this class. It is intended primarily for those who are implementing an ExecutorService. Most users should call ListeningExecutorService.submit on a service obtained from MoreExecutors.listeningDecorator(java.util.concurrent.ExecutorService).

Since:
1.0
Author:
Sven Mawson

  • Method Details

    • create

      public static <V extends @Nullable Object> ListenableFutureTask<V> create(Callable<V> callable)
      Creates a ListenableFutureTask that will upon running, execute the given Callable.
      Parameters:
      callable - the callable task
      Since:
      10.0

    • create

      public static <V extends @Nullable Object> ListenableFutureTask<V> create(Runnable runnable, V result)
      Creates a ListenableFutureTask that will upon running, execute the given Runnable, and arrange that get will return the given result on successful completion.
      Parameters:
      runnable - the runnable task
      result - the result to return on successful completion. If you don't need a particular result, consider using constructions of the form: ListenableFuture<?> f = ListenableFutureTask.create(runnable, null)
      Since:
      10.0

    • addListener

      public void addListener(Runnable listener, Executor exec)
      Description copied from interface: ListenableFuture
      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: If your listener is lightweight -- and will not cause stack overflow by completing more futures or adding more directExecutor() listeners inline -- consider MoreExecutors.directExecutor(). Otherwise, avoid it: See the warnings on the docs for directExecutor.

      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.

      Guava implementations of ListenableFuture promptly release references to listeners after executing them.

      Specified by:
      addListener in interface ListenableFuture<V extends @Nullable Object>
      Parameters:
      listener - the listener to run when the computation is complete
      exec - the executor to run the listener in

    • get

      @CanIgnoreReturnValue public V get(long timeout, TimeUnit unit) throws TimeoutException, InterruptedException, ExecutionException
      Specified by:
      get in interface Future<V extends @Nullable Object>
      Overrides:
      get in class FutureTask<V extends @Nullable Object>
      Throws:
      TimeoutException
      InterruptedException
      ExecutionException

    • done

      protected void done()
      Internal implementation detail used to invoke the listeners.
      Overrides:
      done in class FutureTask<V extends @Nullable Object>