org.openzen.zengarden.promise

Interface Promise<R,S,E extends java.lang.Throwable>

Type Parameters:

R - result type

S - status type

E - error type

All Known Implementing Classes:

ProcessedPromise, RejectedPromise, ResolvedPromise

public interface Promise<R,S,E extends java.lang.Throwable>

Contains a promise. Promises are returned to the calling party and provide them with the ability to react on the success, failure, cached values and status updates of a asynchronous task in progress.

Method Summary

Modifier and Type	Method and Description
R	get() Retrieves a result synchronously.
java.lang.Class<E>	getErrorClass() Retrieves the error class.
Promise<R,S,E>	onCached(Consumer<R> consumer) Registers a consumer to be called when cached data becomes available.
default Promise<R,S,E>	onData(Consumer<R> consumer) Registers a consumer to be called when data becomes available, no matter if it's cached or not.
Promise<R,S,E>	onDone(Consumer<R> consumer) Registers a consumer to be called when the call has finished.
Promise<R,S,E>	onFail(Consumer<E> consumer) Registers a consumer to be called when an error occurs.
Promise<R,S,E>	onStatus(Consumer<S> consumer) Registers a consumer to be called when status updates are available.
default <R2> Promise<R2,S,E>	pipe(ErrorableFunction<R,R2,E> function) Creates a processed promise.

Method Detail

getErrorClass

java.lang.Class<E> getErrorClass()

Retrieves the error class. Used to perform proper error handling.

Returns:

error class

onDone

Promise<R,S,E> onDone(Consumer<R> consumer)

Registers a consumer to be called when the call has finished. The consumer might be called immediately.

Parameters:

consumer - result consumer

Returns:

this promise

onCached

Promise<R,S,E> onCached(Consumer<R> consumer)

Registers a consumer to be called when cached data becomes available. The consumer might be called immediately.

Parameters:

consumer - cached value consumer

Returns:

this promise

onData

default Promise<R,S,E> onData(Consumer<R> consumer)

Registers a consumer to be called when data becomes available, no matter if it's cached or not. This method might be called twice, once, or not at all (if an error occurs).

Parameters:

consumer - data consumer

Returns:

this promise

onStatus

Promise<R,S,E> onStatus(Consumer<S> consumer)

Registers a consumer to be called when status updates are available. This consumer might be called any number of times, or not at all.

Parameters:

consumer - status consumer

Returns:

this promise

onFail

Promise<R,S,E> onFail(Consumer<E> consumer)

Registers a consumer to be called when an error occurs.

Parameters:

consumer - error consumer

Returns:

this promise

get

R get()
throws E extends java.lang.Throwable

Retrieves a result synchronously. Might wait return a result immediately, wait until one is a available, or throw an exception if an error occurs.

Returns:

resulting value

Throws:

E - if the request failed

E extends java.lang.Throwable

pipe

default <R2> Promise<R2,S,E> pipe(ErrorableFunction<R,R2,E> function)

Creates a processed promise. This promise will then have its result passed through the given function and passed on to the promise returned by this function called.

Type Parameters:

R2 - new promise data type

Parameters:

function - processing function

Returns:

processed function