org.openzen.zengarden.promise

Class Deferred<T,S,E extends java.lang.Throwable>

java.lang.Object

org.openzen.zengarden.promise.Deferred<T,S,E>

Type Parameters:

T - result type

S - status type

E - error type

public class Deferred<T,S,E extends java.lang.Throwable>
extends java.lang.Object

Represents a deferred value, for asynchronous handling of data. Results and errors are by default posted immediately, but a runner can be provided if results should be run on e.g. an event loop. Deferreds can post cached results as well. This functionality can be used if a local cached value is available yet the actual value is still to be retrieved from another (eg. online) source. Deferreds can also post status updates. These can be used to update user interfaces with the request progress.

Constructor Summary

Constructors

Constructor and Description
Deferred(java.lang.Class<E> errorClass) Constructs a basic deferred.
Deferred(java.lang.Class<E> errorClass, Consumer<java.lang.Runnable> runner) Constructs a deferred with a specified runner.

Method Summary

Modifier and Type	Method and Description
void	cached(T cachedValue) Published a cached value.
Promise<T,S,E>	promise() Returns the promise for this deferred.
void	reject(E error) Publishes an error.
void	resolve(T response) Publishes a result.
void	status(S status) Publishes a status update.

Methods inherited from class java.lang.Object

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

Constructor Detail

Deferred

public Deferred(java.lang.Class<E> errorClass)

Constructs a basic deferred. Results, cached values, status updates and errors will be posted immediately.

Parameters:

errorClass - exception class

Deferred

public Deferred(java.lang.Class<E> errorClass,
                Consumer<java.lang.Runnable> runner)

Constructs a deferred with a specified runner. The runner is called whenever a result, cached value, status update or error is to be posted.

Parameters:

errorClass - exception class

runner - post runner

Method Detail

cached

public void cached(T cachedValue)

Published a cached value.

Parameters:

cachedValue - value to be published

resolve

public void resolve(T response)

Publishes a result.

Parameters:

response - value to be published

status

public void status(S status)

Publishes a status update.

Parameters:

status - status to be published

reject

public void reject(E error)

Publishes an error.

Parameters:

error - error to be published

promise

public Promise<T,S,E> promise()

Returns the promise for this deferred.

Returns:

this deferred's promise