Package com.google.common.util.concurrent

Class ListenableFutureTask<V extends @Nullable java.lang.Object>

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addListener​(java.lang.Runnable listener, java.util.concurrent.Executor exec)
      Registers a listener to be run on the given executor.
      static <V extends @Nullable java.lang.Object>
      ListenableFutureTask<V>      		 create​(java.lang.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.
      static <V extends @Nullable java.lang.Object>
      ListenableFutureTask<V>      		 create​(java.util.concurrent.Callable<V> callable)
      Creates a ListenableFutureTask that will upon running, execute the given Callable.
      protected void done()
      Internal implementation detail used to invoke the listeners.
      V get​(long timeout, java.util.concurrent.TimeUnit unit)
      Waits if necessary for at most the given time for the computation to complete, and then retrieves its result, if available.

      • Methods inherited from class java.util.concurrent.FutureTask

        cancel, get, isCancelled, isDone, run, runAndReset, set, setException, toString

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

      • Methods inherited from interface java.util.concurrent.Future

        cancel, get, isCancelled, isDone

    • Method Detail

      • create

        public static <V extends @Nullable java.lang.Object> ListenableFutureTask<V> create​(java.util.concurrent.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 java.lang.Object> ListenableFutureTask<V> create​(java.lang.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​(java.lang.Runnable listener,
                        java.util.concurrent.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 java.lang.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,
             java.util.concurrent.TimeUnit unit)
      throws java.util.concurrent.TimeoutException,
             java.lang.InterruptedException,
             java.util.concurrent.ExecutionException
        Description copied from interface: java.util.concurrent.Future
        Waits if necessary for at most the given time for the computation to complete, and then retrieves its result, if available.
        Specified by:
        get in interface java.util.concurrent.Future<V extends @Nullable java.lang.Object>
        Overrides:
        get in class java.util.concurrent.FutureTask<V extends @Nullable java.lang.Object>
        Parameters:
        timeout - the maximum time to wait
        unit - the time unit of the timeout argument
        Returns:
        the computed result
        Throws:
        java.util.concurrent.TimeoutException - if the wait timed out
        java.lang.InterruptedException - if the current thread was interrupted while waiting
        java.util.concurrent.ExecutionException - if the computation threw an exception

      • done

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