software.amazon.awssdk.utils

Class CompletableFutureUtils

java.lang.Object

software.amazon.awssdk.utils.CompletableFutureUtils

public final class CompletableFutureUtils
extends Object

Utility class for working with CompletableFuture.

Method Summary

Modifier and Type	Method and Description
static CompletableFuture<Void>	allOfExceptionForwarded(CompletableFuture<?>[] futures) Similar to CompletableFuture.allOf(CompletableFuture[]), but when any future is completed exceptionally, forwards the exception to other futures.
static CompletionException	errorAsCompletionException(Throwable t) Wraps the given error in a CompletionException if necessary.
static <U> CompletableFuture<U>	failedFuture(Throwable t) Convenience method for creating a future that is immediately completed exceptionally with the given Throwable.
static <T> CompletableFuture<T>	forwardExceptionTo(CompletableFuture<T> src, CompletableFuture<?> dst) Forward the Throwable from src to dst.
static <T> CompletableFuture<T>	forwardResultTo(CompletableFuture<T> src, CompletableFuture<T> dst) Completes the dst future based on the result of the src future asynchronously on the provided Executor and return the src future.
static <T> CompletableFuture<T>	forwardResultTo(CompletableFuture<T> src, CompletableFuture<T> dst, Executor executor) Completes the dst future based on the result of the src future asynchronously on the provided Executor and return the src future.
static <T> CompletableFuture<T>	forwardTransformedExceptionTo(CompletableFuture<T> src, CompletableFuture<?> dst, Function<Throwable,Throwable> transformationFunction) Forward the Throwable that can be transformed as per the transformationFunction from src to dst.
static <SourceT,DestT> CompletableFuture<SourceT>	forwardTransformedResultTo(CompletableFuture<SourceT> src, CompletableFuture<DestT> dst, Function<SourceT,DestT> function) Completes the dst future based on the result of the src future, synchronously, after applying the provided transformation Function if successful.
static <T> T	joinInterruptibly(CompletableFuture<T> future)
static void	joinInterruptiblyIgnoringFailures(CompletableFuture<?> future)

Methods inherited from class java.lang.Object

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

Method Detail

failedFuture

public static <U> CompletableFuture<U> failedFuture(Throwable t)

Convenience method for creating a future that is immediately completed exceptionally with the given Throwable.

Similar to CompletableFuture#failedFuture which was added in Java 9.

Type Parameters:

U - The type of the element.

Parameters:

t - The failure.

Returns:

The failed future.

errorAsCompletionException

public static CompletionException errorAsCompletionException(Throwable t)

Wraps the given error in a CompletionException if necessary. Useful if an exception needs to be rethrown from within CompletableFuture.handle(java.util.function.BiFunction) or similar methods.

Parameters:

t - The error.

Returns:

The error as a CompletionException.

forwardExceptionTo

public static <T> CompletableFuture<T> forwardExceptionTo(CompletableFuture<T> src,
                                                          CompletableFuture<?> dst)

Forward the Throwable from src to dst.

Parameters:

src - The source of the Throwable.

dst - The destination where the Throwable will be forwarded to.

Returns:

src.

forwardTransformedExceptionTo

public static <T> CompletableFuture<T> forwardTransformedExceptionTo(CompletableFuture<T> src,
                                                                     CompletableFuture<?> dst,
                                                                     Function<Throwable,Throwable> transformationFunction)

Forward the Throwable that can be transformed as per the transformationFunction from src to dst.

Parameters:

src - The source of the Throwable.

dst - The destination where the Throwable will be forwarded to

transformationFunction - Transformation function taht will be applied on to the forwarded exception.

Returns:

forwardResultTo

public static <T> CompletableFuture<T> forwardResultTo(CompletableFuture<T> src,
                                                       CompletableFuture<T> dst)

Completes the dst future based on the result of the src future asynchronously on the provided Executor and return the src future.

Parameters:

src - The source CompletableFuture

dst - The destination where the Throwable or response will be forwarded to.

Returns:

the src future.

forwardResultTo

public static <T> CompletableFuture<T> forwardResultTo(CompletableFuture<T> src,
                                                       CompletableFuture<T> dst,
                                                       Executor executor)

Completes the dst future based on the result of the src future asynchronously on the provided Executor and return the src future.

Parameters:

src - The source CompletableFuture

dst - The destination where the Throwable or response will be forwarded to.

executor - the executor to complete the des future

Returns:

the src future.

forwardTransformedResultTo

public static <SourceT,DestT> CompletableFuture<SourceT> forwardTransformedResultTo(CompletableFuture<SourceT> src,
                                                                                    CompletableFuture<DestT> dst,
                                                                                    Function<SourceT,DestT> function)

Completes the dst future based on the result of the src future, synchronously, after applying the provided transformation Function if successful.

Parameters:

src - The source CompletableFuture

dst - The destination where the Throwable or transformed result will be forwarded to.

Returns:

the src future.

allOfExceptionForwarded

public static CompletableFuture<Void> allOfExceptionForwarded(CompletableFuture<?>[] futures)

Similar to CompletableFuture.allOf(CompletableFuture[]), but when any future is completed exceptionally, forwards the exception to other futures.

Parameters:

futures - The futures.

Returns:

The new future that is completed when all the futures in futures are.

joinInterruptibly

public static <T> T joinInterruptibly(CompletableFuture<T> future)

joinInterruptiblyIgnoringFailures

public static void joinInterruptiblyIgnoringFailures(CompletableFuture<?> future)