com.linkedin.parseq.promise

Class Promises

java.lang.Object

com.linkedin.parseq.promise.Promises

public class Promises
extends Object

This class provides a set of static helper methods that make it easier to work with Promises.

Author:

Chris Pettitt ([email protected]), Jaroslaw Odzga ([email protected])

Field Summary

Fields

Modifier and Type	Field and Description
static Promise<Void>	VOID

Method Summary

Modifier and Type	Method and Description
static <T> Promise<T>	error(Throwable error) Creates a new promise that is already resolved with the given error.
static <T> void	propagateResult(Promise<T> source, Settable<T> dest) Copies the value or error from the source promise to the destination promise.
static <T> void	propagateResult(Promise<T> source, SettablePromise<T> dest)
static <T> SettablePromise<T>	settable() Returns a new promise that can have its value set at a later time.
static <T> Try<T>	toTry(Promise<T> promise) Returns instance of Try that represents result a promise has completed with.
static <T> Promise<T>	value(T value) Creates a new promise that is already resolved with the given value.

Methods inherited from class java.lang.Object

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

Field Detail

VOID

public static final Promise<Void> VOID

Method Detail

value

public static <T> Promise<T> value(T value)

Creates a new promise that is already resolved with the given value.

Type Parameters:

T - the type of the value for the promise

Parameters:

value - the value for the new promise

Returns:

the promise

error

public static <T> Promise<T> error(Throwable error)

Creates a new promise that is already resolved with the given error.

Type Parameters:

T - the type of the value for the promise

Parameters:

error - the error for the new promise

Returns:

the promise

settable

public static <T> SettablePromise<T> settable()

Returns a new promise that can have its value set at a later time.

Type Parameters:

T - the type of the value for the promise

Returns:

the promise

propagateResult

public static <T> void propagateResult(Promise<T> source,
                                       Settable<T> dest)

Copies the value or error from the source promise to the destination promise.

Type Parameters:

T - the value type for both promises

Parameters:

source - the source promise

dest - the destination promise

propagateResult

public static <T> void propagateResult(Promise<T> source,
                                       SettablePromise<T> dest)

toTry

public static <T> Try<T> toTry(Promise<T> promise)

Returns instance of Try that represents result a promise has completed with. This method throws PromiseUnresolvedException if teh promise has not been resolved yet.

Returns:

instance of Try that represents result the promise has completed with

See Also:

Try