Class CompletionStages


public class CompletionStages extends Object
Utility methods for handling CompletionStage instances.
  • Field Details


      public static final Runnable NO_OP_RUNNABLE
  • Method Details

    • aggregateCompletionStage

      public static AggregateCompletionStage<Void> aggregateCompletionStage()
      Returns a CompletionStage that also can be composed of many other CompletionStages. A stage can compose another stage in it by invoking the AggregateCompletionStage.dependsOn(CompletionStage) method passing in the CompletionStage. After all stages this composition stage depend upon have been added, the AggregateCompletionStage.freeze() should be invoked so that the AggregateCompletionStage can finally complete when all of the stages it depends upon complete.

      If any stage this depends upon fails the returned stage will contain the Throwable from one of the stages.

      composed completion stage
    • aggregateCompletionStage

      public static <R> AggregateCompletionStage<R> aggregateCompletionStage(R valueToReturn)
      Same as aggregateCompletionStage() except that when this stage completes normally it will return the value provided.
      Type Parameters:
      R - the type of the value
      valueToReturn - value to return to future stage compositions
      composed completion stage that returns the value upon normal completion
    • orBooleanAggregateCompletionStage

      public static AggregateCompletionStage<Boolean> orBooleanAggregateCompletionStage()
    • isCompletedSuccessfully

      public static boolean isCompletedSuccessfully(CompletionStage<?> stage)
      Returns if the provided CompletionStage has already completed normally, that is not due to an exception.
      stage - stage to check
      if the stage is completed normally
    • join

      public static <R> R join(CompletionStage<R> stage)
      Returns the result value when complete, or throws an (unchecked) exception if completed exceptionally. To better conform with the use of common functional forms, if a computation involved in the completion of this CompletionStage threw an exception, this method throws an (unchecked) CompletionException with the underlying exception as its cause.
      Type Parameters:
      R - the type in the stage
      stage - stage to wait on
      the result value
      CompletionException - if this stage completed exceptionally or a completion computation threw an exception
    • allOf

      public static CompletionStage<Void> allOf(CompletionStage<Void> first, CompletionStage<Void> second)
      Returns a CompletableStage that completes when both of the provides CompletionStages complete. This method may choose to return either of the argument if the other is complete or a new instance completely.
      first - the first CompletionStage
      second - the second CompletionStage
      a CompletionStage that is complete when both of the given CompletionStages complete
    • allOf

      public static CompletionStage<Void> allOf(CompletionStage<?>... stages)
      Returns a CompletionStage that completes when all of the provided stages complete, either normally or via exception. If one or more states complete exceptionally the returned CompletionStage will complete with the exception of one of these. If no CompletionStages are provided, returns a CompletionStage completed with the value null.
      stages - the CompletionStages
      a CompletionStage that is completed when all of the given CompletionStages complete
    • handleAndCompose

      public static <T, U> CompletionStage<U> handleAndCompose(CompletionStage<T> stage, BiFunction<T,Throwable,CompletionStage<U>> handleFunction)
      Extend CompletionStage.thenCompose(Function) to also handle exceptions.
    • handleAndComposeAsync

      public static <T, U> CompletionStage<U> handleAndComposeAsync(CompletionStage<T> stage, BiFunction<T,Throwable,CompletionStage<U>> handleFunction, Executor executor)
    • schedule

      public static CompletionStage<Void> schedule(Runnable command, ScheduledExecutorService executor, long delay, TimeUnit timeUnit)
    • schedule

      public static <T> CompletionStage<T> schedule(Callable<T> command, ScheduledExecutorService executor, long delay, TimeUnit timeUnit)
    • scheduleNonBlocking

      public static <T> CompletionStage<T> scheduleNonBlocking(Callable<? extends CompletionStage<T>> command, ScheduledExecutorService executor, long delay, TimeUnit timeUnit)
    • ignoreValue

      public static CompletionStage<Void> ignoreValue(CompletionStage<?> stage)
    • await

      public static <T> T await(CompletionStage<T> stage) throws ExecutionException, InterruptedException
    • performSequentially

      public static <I> CompletionStage<Void> performSequentially(Iterator<I> iterator, Function<? super I,CompletionStage<Void>> function)
    • performSequentially

      public static <I, T, A, R> CompletionStage<R> performSequentially(Iterator<I> iterator, Function<? super I,CompletionStage<T>> function, Collector<T,A,R> collector)