org.eclipse.microprofile.reactive.messaging

Interface Emitter<T>

Type Parameters:

T - type of payload

All Superinterfaces:

EmitterBehavior

public interface Emitter<T>
extends EmitterBehavior

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

Instances are injected using:

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

You can use an injected emitter to send either payloads or Messages.

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

The OnOverflow annotation can be used to configure what to do if messages are sent using the `Emitter` when a downstream subscriber hasn't requested more messages.

Method Summary

Modifier and Type	Method and Description
<M extends Message<? extends T>> void	send(M msg) Sends a message to the channel.
CompletionStage<Void>	send(T msg) Sends a payload to the channel.

Methods inherited from interface io.smallrye.reactive.messaging.EmitterBehavior

complete, error, hasRequests, isCancelled

Method Detail

send

CompletionStage<Void> send(T msg)

Sends a payload to the channel.

A Message object will be created to hold the payload and the returned CompletionStage will be completed once this Message is acknowledged. If the Message is never acknowledged, then the CompletionStage will never be completed.

Parameters:

msg - the thing to send, must not be null

Returns:

the CompletionStage, which will be completed when the message for this payload is acknowledged.

Throws:

IllegalStateException - if the channel has been cancelled or terminated or if an overflow strategy of THROW_EXCEPTION or BUFFER is configured and the emitter overflows.

send

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

Sends a message 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 cancelled or terminated or if an overflow strategy of THROW_EXCEPTION or BUFFER is configured and the emitter overflows.