com.atlassian.util.concurrent
Class Promises

java.lang.Object
  com.atlassian.util.concurrent.Promises

@Beta
public final class Promises
extends java.lang.Object

Library of utility Promise functions

Since:

2.4

Method Summary

static <A> Promise<A>	forFuture(java.util.concurrent.Future<A> future) Creates a promise from the given future.
static <A> Promise<A>	forListenableFuture(com.google.common.util.concurrent.ListenableFuture<A> future) Creates a promise from the given future.
static <A> com.google.common.util.concurrent.FutureCallback<A>	futureCallback(Effect<A> success, Effect<java.lang.Throwable> failure) Create a FutureCallback by composing two Effects.
static <A> com.google.common.util.concurrent.FutureCallback<A>	onFailureDo(Effect<java.lang.Throwable> effect) Create a FutureCallback from an Effect to be run if there is a failure.
static <A> com.google.common.util.concurrent.FutureCallback<A>	onSuccessDo(Effect<A> effect) Create a FutureCallback from an Effect to be run if there is a success.
static <A> Promise<A>	promise(A value) Creates a new, resolved promise for the specified concrete value.
static Effect<java.lang.Throwable>	reject(com.google.common.util.concurrent.SettableFuture<?> delegate) Creates a new Effect that forwards a promise's fail events to the specified future delegate's SettableFuture.setException(Throwable) method -- that is, the new callback rejects the delegate future if invoked.
static <A> Promise<A>	rejected(java.lang.Throwable throwable, java.lang.Class<A> resultType) Creates a new, rejected promise from the given Throwable and result type.
static <A> Promise<A>	toRejectedPromise(java.lang.Throwable t, java.lang.Class<A> resultType) Creates a new, rejected promise from the given Throwable and result type.
static <A> Promise<A>	toResolvedPromise(A value) Creates a new, resolved promise for the specified concrete value.
static <A> Promise<java.util.List<A>>	when(java.lang.Iterable<? extends Promise<? extends A>> promises) Returns a new Promise representing the status of a list of other promises.
static <A> Promise<java.util.List<A>>	when(Promise<? extends A>... promises) Returns a new Promise representing the status of a list of other promises.

Methods inherited from class java.lang.Object

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

Method Detail

when

public static <A> Promise<java.util.List<A>> when(Promise<? extends A>... promises)

Returns a new Promise representing the status of a list of other promises.

Parameters:

promises - The promises that the new promise should track

Returns:

The new, aggregate promise

when

public static <A> Promise<java.util.List<A>> when(java.lang.Iterable<? extends Promise<? extends A>> promises)

Returns a new Promise representing the status of a list of other promises. More generally this is known as {code}sequence{code} as both List and Promise are traversable monads.

Parameters:

promises - The promises that the new promise should track

Returns:

The new, aggregate promise

promise

public static <A> Promise<A> promise(A value)

Creates a new, resolved promise for the specified concrete value.

Parameters:

value - The value for which a promise should be created

Returns:

The new promise

toResolvedPromise

public static <A> Promise<A> toResolvedPromise(A value)

Creates a new, resolved promise for the specified concrete value.

Synonym for promise(Object).

Parameters:

value - The value for which a promise should be created

Returns:

The new promise

rejected

public static <A> Promise<A> rejected(java.lang.Throwable throwable,
                                      java.lang.Class<A> resultType)

Creates a new, rejected promise from the given Throwable and result type.

Parameters:

throwable - The throwable

resultType - The result type

Returns:

The new promise

toRejectedPromise

public static <A> Promise<A> toRejectedPromise(java.lang.Throwable t,
                                               java.lang.Class<A> resultType)

Creates a new, rejected promise from the given Throwable and result type.

Synonym for rejected(Throwable, Class)

Parameters:

t - The throwable

resultType - The result type

Returns:

The new promise

forListenableFuture

public static <A> Promise<A> forListenableFuture(com.google.common.util.concurrent.ListenableFuture<A> future)

Creates a promise from the given future.

Parameters:

future - The future delegate for the new promise

Returns:

The new promise

forFuture

public static <A> Promise<A> forFuture(java.util.concurrent.Future<A> future)

Creates a promise from the given future.

Parameters:

future - The future delegate for the new promise

Returns:

The new promise

reject

public static Effect<java.lang.Throwable> reject(com.google.common.util.concurrent.SettableFuture<?> delegate)

Creates a new Effect that forwards a promise's fail events to the specified future delegate's SettableFuture.setException(Throwable) method -- that is, the new callback rejects the delegate future if invoked.

Parameters:

delegate - The future to be rejected on a fail event

Returns:

The fail callback

futureCallback

public static <A> com.google.common.util.concurrent.FutureCallback<A> futureCallback(Effect<A> success,
                                                                                     Effect<java.lang.Throwable> failure)

Create a FutureCallback by composing two Effects.

Parameters:

success - To run if the Future is successful

failure - To run if the Future fails

Returns:

The composed futureCallback

onSuccessDo

public static <A> com.google.common.util.concurrent.FutureCallback<A> onSuccessDo(Effect<A> effect)

Create a FutureCallback from an Effect to be run if there is a success.

Parameters:

effect - To be passed the produced value if it happens

Returns:

The FutureCallback with a no-op onFailure

onFailureDo

public static <A> com.google.common.util.concurrent.FutureCallback<A> onFailureDo(Effect<java.lang.Throwable> effect)

Create a FutureCallback from an Effect to be run if there is a failure.

Parameters:

effect - To be passed an exception if it happens

Returns:

The FutureCallback with a no-op onSuccess