Package ratpack.exec

Interface Downstream<T>

Type Parameters:

T - the type of value emitted downstream

All Known Implementing Classes:

Promised

public interface Downstream<T>

A consumer of a single asynchronous value.

Downstreams connect to upstreams. Once connected, an upstream will invoke only one of either the success(T), error(java.lang.Throwable) or complete() methods exactly once.

See Also:

Promise.transform(Function)

Method Summary

Modifier and Type	Method	Description
default void	accept(com.google.common.util.concurrent.ListenableFuture<? extends T> future)	Sends the result of the future downstream.
default void	accept(CompletionStage<? extends T> completionStage)	Sends the result of a CompletionStage downstream.
default void	accept(ExecResult<? extends T> result)	Signals this downstream, based on the given result.
default void	accept(Result<? extends T> result)	Signals this downstream, based on the given result.
void	complete()	Signals that the upstream will not be providing a value, as it has terminated.
default <I extends T,A> CompletionHandler<I,A>	completionHandler()	Creates a JDK CompletionHandler that connects to this downstream.
void	error(Throwable throwable)	Signals the unsuccessful production of the upstream value.
default Downstream<T>	onComplete(Block block)	Wrap this downstream, using the given action as the implementation of the complete() method.
default Downstream<T>	onError(Action<? super Throwable> action)	Wrap this downstream, using the given action as the implementation of the error(Throwable) method.
default <O> Downstream<O>	onSuccess(Action<? super O> action)	Wrap this downstream, using the given action as the implementation of the success(T) method.
void	success(T value)	Signals the successful production of the upstream value.

Method Detail

success

void success(T value)

Signals the successful production of the upstream value.

Parameters:

value - the upstream value

error

void error(Throwable throwable)

Signals the unsuccessful production of the upstream value.

Parameters:

throwable - what went wrong

complete

void complete()

Signals that the upstream will not be providing a value, as it has terminated.

onSuccess

default <O> Downstream<O> onSuccess(Action<? super O> action)

Wrap this downstream, using the given action as the implementation of the success(T) method.

All error(java.lang.Throwable) and complete() signals will be forwarded to this downstream, and the given action called with the value if success(T) is signalled.

Type Parameters:

O - the type of item accepted

Parameters:

action - the implementation of the success signal receiver for the returned downstream

Returns:

a downstream

onError

default Downstream<T> onError(Action<? super Throwable> action)

Wrap this downstream, using the given action as the implementation of the error(Throwable) method.

All success(T) and complete() signals will be forwarded to this downstream, and the given action called with the value if success(T) is signalled.

Parameters:

action - the implementation of the error signal receiver for the returned downstream

Returns:

a downstream

onComplete

default Downstream<T> onComplete(Block block)

Wrap this downstream, using the given action as the implementation of the complete() method.

All success(T) and error(java.lang.Throwable) signals will be forwarded to this downstream, and the given action called with the value if complete() is signalled.

Parameters:

block - the implementation of the complete signal receiver for the returned downstream

Returns:

a downstream

accept

default void accept(ExecResult<? extends T> result)

Signals this downstream, based on the given result.

Parameters:

result - the result to signal

accept

default void accept(Result<? extends T> result)

Signals this downstream, based on the given result.

Parameters:

result - the result to signal

accept

default void accept(CompletionStage<? extends T> completionStage)

Sends the result of a CompletionStage downstream.

Parameters:

completionStage - the CompletionStage to consume the value of

accept

default void accept(com.google.common.util.concurrent.ListenableFuture<? extends T> future)

Sends the result of the future downstream.

Parameters:

future - the future to consume the value of

completionHandler

default <I extends T,A> CompletionHandler<I,A> completionHandler()

Creates a JDK CompletionHandler that connects to this downstream.

Returns:

a completion handler

Since:

1.2