Package play.libs.concurrent

Interface Futures

All Known Implementing Classes:
DefaultFutures
public interface Futures
Utilities for creating CompletionStage operations.

  • Method Details

    • timeout

      <A> CompletionStage<A> timeout(CompletionStage<A> stage, long amount, TimeUnit unit)
      Creates a CompletionStage that returns either the input stage, or a timeout.

      Note that timeout is not the same as cancellation. Even in case of timeout, the given completion stage will still complete, even though that completed value is not returned. 

      
 CompletionStage<Double> callWithTimeout() {
     return futures.timeout(delayByOneSecond(), Duration.ofMillis(300));
 }
      Type Parameters:
      A - the completion's result type.
      Parameters:
      stage - the input completion stage that may time out.
      amount - The amount (expressed with the corresponding unit).
      unit - The time Unit.
      Returns:
      either the completed completion stage, or a completion stage that failed with timeout.

    • timeout

      <A> CompletionStage<A> timeout(CompletionStage<A> stage, Duration duration)
      An alias for timeout that uses a Duration.
      Type Parameters:
      A - the completion stage that should be wrapped with a timeout.
      Parameters:
      stage - the input completion stage that may time out.
      duration - The duration after which there is a timeout.
      Returns:
      the completion stage, or a completion stage that failed with timeout.

    • delayed

      <A> CompletionStage<A> delayed(Callable<CompletionStage<A>> callable, long amount, TimeUnit unit)
      Create a CompletionStage which, after a delay, will be redeemed with the result of a given callable. The completion stage will be called after the delay.
      Type Parameters:
      A - the type of the completion's result.
      Parameters:
      callable - the input completion stage that is called after the delay.
      amount - The time to wait.
      unit - The units to use for the amount.
      Returns:
      the delayed CompletionStage wrapping supplier.

    • delay

      CompletionStage<Done> delay(Duration duration)
      Creates a completion stage which is only completed after the delay. 
      
 Duration expected = Duration.ofSeconds(2);
 long start = System.currentTimeMillis();
 CompletionStage<Long> stage = futures.delay(expected).thenApply((v) -> {
     long end = System.currentTimeMillis();
     return (end - start);
 });
      Parameters:
      duration - the duration after which the completion stage is run.
      Returns:
      the completion stage.

    • delay

      CompletionStage<Done> delay(long amount, TimeUnit unit)
      Creates a completion stage which is only completed after the delay.
      Parameters:
      amount - The time to wait.
      unit - The units to use for the amount.
      Returns:
      the delayed CompletionStage.

    • delayed

      <A> CompletionStage<A> delayed(Callable<CompletionStage<A>> callable, Duration duration)
      Create a CompletionStage which, after a delay, will be redeemed with the result of a given supplier. The completion stage will be called after the delay.

      For example, to render a number indicating the delay, you can use the following method: 

      
 private CompletionStage<Long> renderAfter(Duration duration) {
     long start = System.currentTimeMillis();
     return futures.delayed(() -> {
          long end = System.currentTimeMillis();
          return CompletableFuture.completedFuture(end - start);
     }, duration);
 }
      Type Parameters:
      A - the type of the completion's result.
      Parameters:
      callable - the input completion stage that is called after the delay.
      duration - to wait.
      Returns:
      the delayed CompletionStage wrapping supplier.

    • sequence

      static <A> CompletionStage<List<A>> sequence(Iterable<? extends CompletionStage<A>> promises)
      Combine the given CompletionStages into a single CompletionStage for the list of results.

      The sequencing operations are performed in the default ExecutionContext.

      Type Parameters:
      A - the type of the completion's result.
      Parameters:
      promises - The CompletionStages to combine
      Returns:
      A single CompletionStage whose methods act on the list of redeemed CompletionStages

    • sequence

      @SafeVarargs static <A> CompletionStage<List<A>> sequence(CompletionStage<A>... promises)
      Combine the given CompletionStages into a single CompletionStage for the list of results.

      The sequencing operations are performed in the default ExecutionContext.

      Type Parameters:
      A - the type of the completion's result.
      Parameters:
      promises - The CompletionStages to combine
      Returns:
      A single CompletionStage whose methods act on the list of redeemed CompletionStage