org.eclipse.microprofile.reactive.messaging

Interface Emitter<T>

Type Parameters:

T - type of payload or Message.

All Known Implementing Classes:

EmitterImpl

public interface Emitter<T>

Interface used to feed a stream from an imperative piece of code.

Instances are injected using:

 @Inject
 @Channel("my-channel")
 Emitter<String> emitter;
 

You can inject emitter sending payload or Messages.

The name of the channel (given in the Channel annotation) indicates which streams is fed. It must match the name used in a method using @Incoming or an outgoing stream configured in the application configuration.

Method Summary

Modifier and Type	Method and Description
void	complete() Sends the completion event to the channel indicating that no other events will be sent afterward.
void	error(Exception e) Sends a failure event to the channel.
boolean	isCancelled()
boolean	isRequested()
<M extends Message<? extends T>> void	send(M msg) Sends a payload to the channel.
CompletionStage<Void>	send(T msg) Sends a payload to the channel.

Method Detail

send

CompletionStage<Void> send(T msg)

Sends a payload to the channel.

Parameters:

msg - the thing to send, must not be null

Returns:

the CompletionStage, which will be completed as sending the payload alone does not provide a callback mechanism.

Throws:

IllegalStateException - if the channel has been canceled or terminated.

send

<M extends Message<? extends T>> void send(M msg)

Sends a payload to the channel.

Type Parameters:

M - the Message type

Parameters:

msg - the Message to send, must not be null

Throws:

IllegalStateException - if the channel has been canceled or terminated.

complete

void complete()

Sends the completion event to the channel indicating that no other events will be sent afterward.

error

void error(Exception e)

Sends a failure event to the channel. No more events will be sent afterward.

Parameters:

e - the exception, must not be null

isCancelled

boolean isCancelled()

Returns:

true if the emitter has been terminated or the subscription cancelled.

isRequested

boolean isRequested()

Returns:

true if the subscriber accepts messages, false otherwise. Using send(Object) on an emitter not expecting message would throw an IllegalStateException.