Module dev.mccue.guava.concurrent
Package dev.mccue.guava.concurrent

Class ForwardingListenableFuture<V extends @Nullable Object>

java.lang.Object
dev.mccue.guava.collect.ForwardingObject
dev.mccue.guava.concurrent.ForwardingFuture<V>
dev.mccue.guava.concurrent.ForwardingListenableFuture<V>
All Implemented Interfaces:
ListenableFuture<V>, Future<V>
Direct Known Subclasses:
ForwardingListenableFuture.SimpleForwardingListenableFuture
public abstract class ForwardingListenableFuture<V extends @Nullable Object> extends ForwardingFuture<V> implements ListenableFuture<V>
A ListenableFuture which forwards all its method calls to another future. Subclasses should override one or more methods to modify the behavior of the backing future as desired per the decorator pattern.

Most subclasses can just use SimpleForwardingListenableFuture.

Since:
4.0
Author:
Shardul Deo

  • Constructor Details

    • ForwardingListenableFuture

      protected ForwardingListenableFuture()
      Constructor for use by subclasses.

  • Method Details

    • delegate

      protected abstract ListenableFuture<? extends V> delegate()
      Specified by:
      delegate in class ForwardingFuture<V extends @Nullable Object>

    • addListener

      public void addListener(Runnable listener, Executor exec)
      Description copied from interface: ListenableFuture
      Registers a listener to be Executor#execute(Runnable) run on the given executor. The listener will run when the Future's computation is Future#isDone() 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 MoreExecutors#directExecutor 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 Futures#addCallback 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