Class Futures$


  • public class Futures$
    extends java.lang.Object
    Futures is the Java API for Futures and Promises
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static Futures$ MODULE$
      Static reference to the singleton instance of this Scala object.
    • Constructor Summary

      Constructors 
      Constructor Description
      Futures$()  
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      <T> scala.concurrent.Future<T> failed​(java.lang.Throwable exception)
      creates an already completed Promise with the specified exception
      <T> java.util.concurrent.CompletionStage<T> failedCompletionStage​(java.lang.Throwable ex)
      Creates an already completed CompletionStage with the specified exception
      <T> scala.concurrent.Future<Option<T>> find​(java.lang.Iterable<scala.concurrent.Future<T>> futures, Function<T,​java.lang.Boolean> predicate, scala.concurrent.ExecutionContext executor)
      Returns a Future that will hold the optional result of the first Future with a result that matches the predicate
      <T> scala.concurrent.Future<T> firstCompletedOf​(java.lang.Iterable<scala.concurrent.Future<T>> futures, scala.concurrent.ExecutionContext executor)
      Returns a Future to the result of the first future in the list that is completed
      <T,​R>
      scala.concurrent.Future<R>
      fold​(R zero, java.lang.Iterable<scala.concurrent.Future<T>> futures, Function2<R,​T,​R> fun, scala.concurrent.ExecutionContext executor)
      A non-blocking fold over the specified futures, with the start value of the given zero.
      <T> scala.concurrent.Future<T> future​(java.util.concurrent.Callable<T> body, scala.concurrent.ExecutionContext executor)
      Starts an asynchronous computation and returns a Future object with the result of that computation.
      <T> scala.concurrent.Promise<T> promise()
      Creates a promise object which can be completed with a value.
      <T,​R>
      scala.concurrent.Future<R>
      reduce​(java.lang.Iterable<scala.concurrent.Future<T>> futures, Function2<R,​T,​R> fun, scala.concurrent.ExecutionContext executor)
      Reduces the results of the supplied futures and binary function.
      <A> scala.concurrent.Future<java.lang.Iterable<A>> sequence​(java.lang.Iterable<scala.concurrent.Future<A>> in, scala.concurrent.ExecutionContext executor)
      <T> scala.concurrent.Future<T> successful​(T result)
      Creates an already completed Promise with the specified result
      <A,​B>
      scala.concurrent.Future<java.lang.Iterable<B>>
      traverse​(java.lang.Iterable<A> in, Function<A,​scala.concurrent.Future<B>> fn, scala.concurrent.ExecutionContext executor)
      Transforms a JIterable[A] into a Future[JIterable[B} using the provided Function A => Future[B].
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • MODULE$

        public static final Futures$ MODULE$
        Static reference to the singleton instance of this Scala object.
    • Constructor Detail

      • Futures$

        public Futures$()
    • Method Detail

      • future

        public <T> scala.concurrent.Future<T> future​(java.util.concurrent.Callable<T> body,
                                                     scala.concurrent.ExecutionContext executor)
        Starts an asynchronous computation and returns a Future object with the result of that computation.

        The result becomes available once the asynchronous computation is completed.

        Parameters:
        body - the asynchronous computation
        executor - the execution context on which the future is run
        Returns:
        the Future holding the result of the computation
      • promise

        public <T> scala.concurrent.Promise<T> promise()
        Creates a promise object which can be completed with a value.

        Returns:
        the newly created Promise object
      • failed

        public <T> scala.concurrent.Future<T> failed​(java.lang.Throwable exception)
        creates an already completed Promise with the specified exception
      • successful

        public <T> scala.concurrent.Future<T> successful​(T result)
        Creates an already completed Promise with the specified result
      • failedCompletionStage

        public <T> java.util.concurrent.CompletionStage<T> failedCompletionStage​(java.lang.Throwable ex)
        Creates an already completed CompletionStage with the specified exception
      • find

        public <T> scala.concurrent.Future<Option<T>> find​(java.lang.Iterable<scala.concurrent.Future<T>> futures,
                                                           Function<T,​java.lang.Boolean> predicate,
                                                           scala.concurrent.ExecutionContext executor)
        Returns a Future that will hold the optional result of the first Future with a result that matches the predicate
      • firstCompletedOf

        public <T> scala.concurrent.Future<T> firstCompletedOf​(java.lang.Iterable<scala.concurrent.Future<T>> futures,
                                                               scala.concurrent.ExecutionContext executor)
        Returns a Future to the result of the first future in the list that is completed
      • fold

        public <T,​R> scala.concurrent.Future<R> fold​(R zero,
                                                           java.lang.Iterable<scala.concurrent.Future<T>> futures,
                                                           Function2<R,​T,​R> fun,
                                                           scala.concurrent.ExecutionContext executor)
        A non-blocking fold over the specified futures, with the start value of the given zero. The fold is performed on the thread where the last future is completed, the result will be the first failure of any of the futures, or any failure in the actual fold, or the result of the fold.
      • reduce

        public <T,​R> scala.concurrent.Future<R> reduce​(java.lang.Iterable<scala.concurrent.Future<T>> futures,
                                                             Function2<R,​T,​R> fun,
                                                             scala.concurrent.ExecutionContext executor)
        Reduces the results of the supplied futures and binary function.
      • traverse

        public <A,​B> scala.concurrent.Future<java.lang.Iterable<B>> traverse​(java.lang.Iterable<A> in,
                                                                                   Function<A,​scala.concurrent.Future<B>> fn,
                                                                                   scala.concurrent.ExecutionContext executor)
        Transforms a JIterable[A] into a Future[JIterable[B} using the provided Function A => Future[B]. This is useful for performing a parallel map. For example, to apply a function to all items of a list in parallel.