java8.util.concurrent

Class CompletionStages

java.lang.Object

java8.util.concurrent.CompletionStages

public final class CompletionStages
extends Object

A place for static default implementations of the new Java 12 default interface methods in the CompletionStage interface.

Method Summary

Modifier and Type	Method and Description
static <T> CompletionStage<T>	exceptionallyAsync(CompletionStage<T> thisStage, java8.util.function.Function<Throwable,? extends T> fn) Returns a new CompletionStage that, when thisStage completes exceptionally, is executed with thisStage's exception as the argument to the supplied function, using thisStage's default asynchronous execution facility.
static <T> CompletionStage<T>	exceptionallyAsync(CompletionStage<T> thisStage, java8.util.function.Function<Throwable,? extends T> fn, Executor executor) Returns a new CompletionStage that, when thisStage completes exceptionally, is executed with thisStage's exception as the argument to the supplied function, using the supplied Executor.
static <T> CompletionStage<T>	exceptionallyCompose(CompletionStage<T> thisStage, java8.util.function.Function<Throwable,? extends CompletionStage<T>> fn) Returns a new CompletionStage that, when thisStage completes exceptionally, is composed using the results of the supplied function applied to thisStage's exception.
static <T> CompletionStage<T>	exceptionallyComposeAsync(CompletionStage<T> thisStage, java8.util.function.Function<Throwable,? extends CompletionStage<T>> fn) Returns a new CompletionStage that, when thisStage completes exceptionally, is composed using the results of the supplied function applied to thisStage's exception, using thisStage's default asynchronous execution facility.
static <T> CompletionStage<T>	exceptionallyComposeAsync(CompletionStage<T> thisStage, java8.util.function.Function<Throwable,? extends CompletionStage<T>> fn, Executor executor) Returns a new CompletionStage that, when thisStage completes exceptionally, is composed using the results of the supplied function applied to thisStage's exception, using the supplied Executor.

Methods inherited from class java.lang.Object

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

Method Detail

exceptionallyAsync

public static <T> CompletionStage<T> exceptionallyAsync(CompletionStage<T> thisStage,
                                                        java8.util.function.Function<Throwable,? extends T> fn)

Returns a new CompletionStage that, when thisStage completes exceptionally, is executed with thisStage's exception as the argument to the supplied function, using thisStage's default asynchronous execution facility. Otherwise, if thisStage completes normally, then the returned stage also completes normally with the same value.

Implementation Requirements:
The default implementation invokes CompletionStage.handle(java8.util.function.BiFunction<? super T, java.lang.Throwable, ? extends U>), relaying to CompletionStage.handleAsync(java8.util.function.BiFunction<? super T, java.lang.Throwable, ? extends U>) on exception, then CompletionStage.thenCompose(java8.util.function.Function<? super T, ? extends java8.util.concurrent.CompletionStage<U>>) for result.

Type Parameters:

T - the CompletionStage's element type

Parameters:

thisStage - the CompletionStage to decorate

fn - the function to use to compute the value of the returned CompletionStage if the thisStage CompletionStage completed exceptionally

Returns:

the new CompletionStage

Since:

12

exceptionallyAsync

public static <T> CompletionStage<T> exceptionallyAsync(CompletionStage<T> thisStage,
                                                        java8.util.function.Function<Throwable,? extends T> fn,
                                                        Executor executor)

Returns a new CompletionStage that, when thisStage completes exceptionally, is executed with thisStage's exception as the argument to the supplied function, using the supplied Executor. Otherwise, if thisStage completes normally, then the returned stage also completes normally with the same value.

Implementation Requirements:
The default implementation invokes CompletionStage.handle(java8.util.function.BiFunction<? super T, java.lang.Throwable, ? extends U>), relaying to CompletionStage.handleAsync(java8.util.function.BiFunction<? super T, java.lang.Throwable, ? extends U>) on exception, then CompletionStage.thenCompose(java8.util.function.Function<? super T, ? extends java8.util.concurrent.CompletionStage<U>>) for result.

Type Parameters:

T - the CompletionStage's element type

Parameters:

thisStage - the CompletionStage to decorate

fn - the function to use to compute the value of the returned CompletionStage if the thisStage CompletionStage completed exceptionally

executor - the executor to use for asynchronous execution

Returns:

the new CompletionStage

Since:

12

exceptionallyCompose

public static <T> CompletionStage<T> exceptionallyCompose(CompletionStage<T> thisStage,
                                                          java8.util.function.Function<Throwable,? extends CompletionStage<T>> fn)

Returns a new CompletionStage that, when thisStage completes exceptionally, is composed using the results of the supplied function applied to thisStage's exception.

Implementation Requirements:
The default implementation invokes CompletionStage.handle(java8.util.function.BiFunction<? super T, java.lang.Throwable, ? extends U>), invoking the given function on exception, then CompletionStage.thenCompose(java8.util.function.Function<? super T, ? extends java8.util.concurrent.CompletionStage<U>>) for result.

Type Parameters:

T - the CompletionStage's element type

Parameters:

thisStage - the CompletionStage to compose with

fn - the function to use to compute the returned CompletionStage if the thisStage CompletionStage completed exceptionally

Returns:

the new CompletionStage

Since:

12

exceptionallyComposeAsync

public static <T> CompletionStage<T> exceptionallyComposeAsync(CompletionStage<T> thisStage,
                                                               java8.util.function.Function<Throwable,? extends CompletionStage<T>> fn)

Returns a new CompletionStage that, when thisStage completes exceptionally, is composed using the results of the supplied function applied to thisStage's exception, using thisStage's default asynchronous execution facility.

Implementation Requirements:
The default implementation invokes CompletionStage.handle(java8.util.function.BiFunction<? super T, java.lang.Throwable, ? extends U>), relaying to CompletionStage.handleAsync(java8.util.function.BiFunction<? super T, java.lang.Throwable, ? extends U>) on exception, then CompletionStage.thenCompose(java8.util.function.Function<? super T, ? extends java8.util.concurrent.CompletionStage<U>>) for result.

Type Parameters:

T - the CompletionStage's element type

Parameters:

thisStage - the CompletionStage to compose with

fn - the function to use to compute the returned CompletionStage if the thisStage CompletionStage completed exceptionally

Returns:

the new CompletionStage

Since:

12

exceptionallyComposeAsync

public static <T> CompletionStage<T> exceptionallyComposeAsync(CompletionStage<T> thisStage,
                                                               java8.util.function.Function<Throwable,? extends CompletionStage<T>> fn,
                                                               Executor executor)

Returns a new CompletionStage that, when thisStage completes exceptionally, is composed using the results of the supplied function applied to thisStage's exception, using the supplied Executor.

Implementation Requirements:
The default implementation invokes CompletionStage.handle(java8.util.function.BiFunction<? super T, java.lang.Throwable, ? extends U>), relaying to CompletionStage.handleAsync(java8.util.function.BiFunction<? super T, java.lang.Throwable, ? extends U>) on exception, then CompletionStage.thenCompose(java8.util.function.Function<? super T, ? extends java8.util.concurrent.CompletionStage<U>>) for result.

Type Parameters:

T - the CompletionStage's element type

Parameters:

thisStage - the CompletionStage to compose with

fn - the function to use to compute the returned CompletionStage if the thisStage CompletionStage completed exceptionally

executor - the executor to use for asynchronous execution

Returns:

the new CompletionStage

Since:

12