Package org.eclipse.jetty.util

Interface Promise<C>

Type Parameters:

C - the type of the context object

All Known Implementing Classes:

FuturePromise, HTTPSessionListenerPromise, Promise.Adapter, Promise.Completable, Promise.Wrapper

public interface Promise<C>

A callback abstraction that handles completed/failed events of asynchronous operations.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	Promise.Adapter<U>	Empty implementation of Promise.
static class	Promise.Completable<S>	A CompletableFuture that is also a Promise.
static class	Promise.Wrapper<W>

Field Summary

Fields

Modifier and Type	Field	Description
static final Promise<Object>	NOOP

Method Summary

Modifier and Type	Method	Description
default void	completeWith(CompletableFuture<C> completable)	Completes this promise with the given CompletableFuture.
default void	failed(Throwable x)	Callback invoked when the operation fails.
static <T> Promise<T>	from(CompletableFuture<? super T> completable)	Creates a promise from the given incomplete CompletableFuture.
static <T> Promise<T>	from(Consumer<T> success, Consumer<Throwable> failure)	Creates a Promise from the given success and failure consumers.
static <T> Promise<T>	noop()
default void	succeeded(C result)	Callback invoked when the operation completes.

Field Details

NOOP

static final Promise<Object> NOOP

Method Details

noop

static <T> Promise<T> noop()

succeeded

default void succeeded(C result)

Callback invoked when the operation completes.

Parameters:

result - the context

See Also:

• failed(Throwable)

failed

default void failed(Throwable x)

Callback invoked when the operation fails.

Parameters:

x - the reason for the operation failure

completeWith

default void completeWith(CompletableFuture<C> completable)

Completes this promise with the given CompletableFuture.

When the CompletableFuture completes normally, this promise is succeeded; when the CompletableFuture completes exceptionally, this promise is failed.

Parameters:

completable - the CompletableFuture that completes this promise

from

static <T> Promise<T> from(Consumer<T> success,
 Consumer<Throwable> failure)

Creates a Promise from the given success and failure consumers.

Type Parameters:

T - the type of the result

Parameters:

success - the consumer invoked when the promise is succeeded

failure - the consumer invoked when the promise is failed

Returns:

a new Promise wrapping the success and failure consumers.

from

static <T> Promise<T> from(CompletableFuture<? super T> completable)

Creates a promise from the given incomplete CompletableFuture.

When the promise completes, either succeeding or failing, the CompletableFuture is also completed, respectively via CompletableFuture.complete(Object) or CompletableFuture.completeExceptionally(Throwable).

Type Parameters:

T - the type of the result

Parameters:

completable - the CompletableFuture to convert into a promise

Returns:

a promise that when completed, completes the given CompletableFuture