Class Futures.FutureCombiner<V>

java.lang.Object
com.google.common.util.concurrent.Futures.FutureCombiner<V>
Enclosing class:
Futures

@Beta @GwtCompatible public static final class Futures.FutureCombiner<V> extends Object
A helper to create a new ListenableFuture whose result is generated from a combination of input futures.

See Futures.whenAllComplete(com.google.common.util.concurrent.ListenableFuture<? extends V>...) and Futures.whenAllSucceed(com.google.common.util.concurrent.ListenableFuture<? extends V>...) for how to instantiate this class.

Example:

   
   final ListenableFuture<Instant> loginDateFuture =
       loginService.findLastLoginDate(username);
   final ListenableFuture<List<String>> recentCommandsFuture =
       recentCommandsService.findRecentCommands(username);
   Callable<UsageHistory> usageComputation =
       new Callable<UsageHistory>() {
         public UsageHistory call() throws Exception {
           return new UsageHistory(
               username, loginDateFuture.get(), recentCommandsFuture.get());
         }
       };
   ListenableFuture<UsageHistory> usageFuture =
       Futures.whenAllSucceed(loginDateFuture, recentCommandsFuture)
           .call(usageComputation, executor);
Since:
20.0
  • Method Details

    • callAsync

      public <C> ListenableFuture<C> callAsync(AsyncCallable<C> combiner, Executor executor)
      Creates the ListenableFuture which will return the result of calling AsyncCallable.call() in combiner when all futures complete, using the specified executor.

      If the combiner throws a CancellationException, the returned future will be cancelled.

      If the combiner throws an ExecutionException, the cause of the thrown ExecutionException will be extracted and returned as the cause of the new ExecutionException that gets thrown by the returned combined future.

      Canceling this future will attempt to cancel all the component futures.

    • callAsync

      public <C> ListenableFuture<C> callAsync(AsyncCallable<C> combiner)
    • call

      public <C> ListenableFuture<C> call(Callable<C> combiner, Executor executor)
      Creates the ListenableFuture which will return the result of calling Callable.call() in combiner when all futures complete, using the specified executor.

      If the combiner throws a CancellationException, the returned future will be cancelled.

      If the combiner throws an ExecutionException, the cause of the thrown ExecutionException will be extracted and returned as the cause of the new ExecutionException that gets thrown by the returned combined future.

      Canceling this future will attempt to cancel all the component futures.

    • call

      public <C> ListenableFuture<C> call(Callable<C> combiner)