org.opendaylight.infrautils.utils.concurrent

Class CompletableFutures

java.lang.Object

org.opendaylight.infrautils.utils.concurrent.CompletableFutures

public final class CompletableFutures
extends Object

Utilities for CompletableFuture.

Author:

Michael Vorburger.ch

Method Summary

Modifier and Type	Method and Description
static <T> CompletableFuture<T>	completedExceptionally(Throwable throwable) Return an immediately exceptional completed CompletableFuture.
static <V> com.google.common.util.concurrent.ListenableFuture<V>	toListenableFuture(CompletableFuture<V> completableFuture) Converts a Java 8 CompletionStage to a Guava ListenableFuture.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

toListenableFuture

public static <V> com.google.common.util.concurrent.ListenableFuture<V> toListenableFuture(CompletableFuture<V> completableFuture)

Converts a Java 8 CompletionStage to a Guava ListenableFuture. See CompletionStages.toListenableFuture(CompletionStage) for a related function.

completedExceptionally

public static <T> CompletableFuture<T> completedExceptionally(Throwable throwable)

Return an immediately exceptional completed CompletableFuture.

Inspired by Guava's Futures.immediateFailedFuture(Throwable).

Useful because while CompletableFuture does have a CompletableFuture.completedFuture(Object) static factory method to obtain immediate non-exceptional value completion, it is missing a static factory method like this. This is often useful, e.g. when catching exceptions to transform into CompletableFuture to return, and saves the 3 lines to create a new instance, invoke the non-static CompletableFuture.completeExceptionally(Throwable) and return the completableFuture. (It's not possible to use chained invocation style, because completeExceptionally does not return this but a boolean, which is useless when requiring an immediately completed CompletionStage.)