io.smallrye.reactive.messaging.annotations

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
 @Stream("my-stream")
 Emitter<String> emitter;
 

You can inject emitter sending payload or Messages.

The name of the stream (given in the Stream annotation) indicates which streams is fed. If 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() Completes the stream.
void	error(Exception e) Propagates an error in the stream.
boolean	isCancelled()
boolean	isRequested()
Emitter<T>	send(T msg) Sends a payload or a message to the stream.

Method Detail

send

Emitter<T> send(T msg)

Sends a payload or a message to the stream.

Parameters:

msg - the thing to send, must not be null

Returns:

the current emitter

Throws:

IllegalStateException - if the stream does not have any pending requests, or if the stream has been cancelled or terminated.

complete

void complete()

Completes the stream. This method sends the completion signal, no messages can be sent once this method is called.

error

void error(Exception e)

Propagates an error in the stream. This methods sends an error signal, no messages can be sent once this method is called.

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.