org.apache.beam.sdk.util

Class MoreFutures

java.lang.Object

org.apache.beam.sdk.util.MoreFutures

public class MoreFutures
extends java.lang.Object

Utilities to do future programming with Java 8.

Standards for these utilities:

• Always allow thrown exceptions, and they should cause futures to complete exceptionally.
• Always return CompletionStage as a future value.
• Return CompletableFuture only to the producer of a future value.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MoreFutures.ExceptionOrResult<T> An object that represents either a result or an exceptional termination.

Constructor Summary

Constructors

Constructor and Description
MoreFutures()

Method Summary

Modifier and Type	Method and Description
static <T> java.util.concurrent.CompletionStage<java.util.List<T>>	allAsList(java.util.Collection<? extends java.util.concurrent.CompletionStage<? extends T>> futures) Like CompletableFuture.allOf(java.util.concurrent.CompletableFuture<?>...) but returning the result of constituent futures.
static <T> java.util.concurrent.CompletionStage<java.util.List<MoreFutures.ExceptionOrResult<T>>>	allAsListWithExceptions(java.util.Collection<? extends java.util.concurrent.CompletionStage<? extends T>> futures) Like allAsList(java.util.Collection<? extends java.util.concurrent.CompletionStage<? extends T>>) but return a list .
static <T> T	get(java.util.concurrent.CompletionStage<T> future) Gets the result of the given future.
static <T> T	get(java.util.concurrent.CompletionStage<T> future, long duration, java.util.concurrent.TimeUnit unit) Gets the result of the given future.
static boolean	isCancelled(java.util.concurrent.CompletionStage<?> future) Indicates whether the future is cancelled.
static boolean	isDone(java.util.concurrent.CompletionStage<?> future) Indicates whether the future is done.
static java.util.concurrent.CompletionStage<java.lang.Void>	runAsync(ThrowingRunnable runnable) Shorthand for runAsync(ThrowingRunnable, ExecutorService) using ForkJoinPool.commonPool().
static java.util.concurrent.CompletionStage<java.lang.Void>	runAsync(ThrowingRunnable runnable, java.util.concurrent.ExecutorService executorService) Like CompletableFuture.runAsync(java.lang.Runnable) but for ThrowingRunnable.
static <T> java.util.concurrent.CompletionStage<T>	supplyAsync(ThrowingSupplier<T> supplier) Shorthand for supplyAsync(ThrowingSupplier, ExecutorService) using ForkJoinPool.commonPool().
static <T> java.util.concurrent.CompletionStage<T>	supplyAsync(ThrowingSupplier<T> supplier, java.util.concurrent.ExecutorService executorService) Like CompletableFuture.supplyAsync(Supplier) but for ThrowingSupplier.

Methods inherited from class java.lang.Object

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

Constructor Detail

MoreFutures

public MoreFutures()

Method Detail

get

public static <T> T get(java.util.concurrent.CompletionStage<T> future)
                 throws java.lang.InterruptedException,
                        java.util.concurrent.ExecutionException

Gets the result of the given future.

This utility is provided so consumers of futures need not even convert to CompletableFuture, an interface that is only suitable for producers of futures.

Throws:

java.lang.InterruptedException

java.util.concurrent.ExecutionException

get

public static <T> T get(java.util.concurrent.CompletionStage<T> future,
                        long duration,
                        java.util.concurrent.TimeUnit unit)
                 throws java.lang.InterruptedException,
                        java.util.concurrent.ExecutionException,
                        java.util.concurrent.TimeoutException

Gets the result of the given future.

This utility is provided so consumers of futures need not even convert to CompletableFuture, an interface that is only suitable for producers of futures.

Throws:

java.lang.InterruptedException

java.util.concurrent.ExecutionException

java.util.concurrent.TimeoutException

isDone

public static boolean isDone(java.util.concurrent.CompletionStage<?> future)

Indicates whether the future is done.

This utility is provided so consumers of futures need not even convert to CompletableFuture, an interface that is only suitable for producers of futures.

isCancelled

public static boolean isCancelled(java.util.concurrent.CompletionStage<?> future)

Indicates whether the future is cancelled.

This utility is provided so consumers of futures need not even convert to CompletableFuture, an interface that is only suitable for producers of futures.

supplyAsync

public static <T> java.util.concurrent.CompletionStage<T> supplyAsync(ThrowingSupplier<T> supplier,
                                                                      java.util.concurrent.ExecutorService executorService)

Like CompletableFuture.supplyAsync(Supplier) but for ThrowingSupplier.

If the ThrowingSupplier throws an exception, the future completes exceptionally.

supplyAsync

public static <T> java.util.concurrent.CompletionStage<T> supplyAsync(ThrowingSupplier<T> supplier)

Shorthand for supplyAsync(ThrowingSupplier, ExecutorService) using ForkJoinPool.commonPool().

runAsync

public static java.util.concurrent.CompletionStage<java.lang.Void> runAsync(ThrowingRunnable runnable,
                                                                            java.util.concurrent.ExecutorService executorService)

Like CompletableFuture.runAsync(java.lang.Runnable) but for ThrowingRunnable.

If the ThrowingRunnable throws an exception, the future completes exceptionally.

runAsync

public static java.util.concurrent.CompletionStage<java.lang.Void> runAsync(ThrowingRunnable runnable)

Shorthand for runAsync(ThrowingRunnable, ExecutorService) using ForkJoinPool.commonPool().

allAsList

public static <T> java.util.concurrent.CompletionStage<java.util.List<T>> allAsList(java.util.Collection<? extends java.util.concurrent.CompletionStage<? extends T>> futures)

Like CompletableFuture.allOf(java.util.concurrent.CompletableFuture<?>...) but returning the result of constituent futures.

allAsListWithExceptions

public static <T> java.util.concurrent.CompletionStage<java.util.List<MoreFutures.ExceptionOrResult<T>>> allAsListWithExceptions(java.util.Collection<? extends java.util.concurrent.CompletionStage<? extends T>> futures)

Like allAsList(java.util.Collection<? extends java.util.concurrent.CompletionStage<? extends T>>) but return a list .