Supported signatures

The following tables list the supported method signatures and indicate the various supported features. For instance, they indicate the default and available acknowledgement strategies (when applicable).

Method signatures to generate data

Signature	Invocation time
@Outgoing Publisher<Message<O>> method() `	Called once at assembly time
@Outgoing Publisher<O> method() `	Called once at assembly time
@Outgoing Multi<Message<O>> method() `	Called once at assembly time
@Outgoing Multi<O> method() `	Called once at assembly time
@Outgoing Flow.Publisher<Message<O>> method() `	Called once at assembly time
@Outgoing Flow.Publisher<O> method() `	Called once at assembly time
@Outgoing PublisherBuilder<Message<O>> method() `	Called once at assembly time
@Outgoing PublisherBuilder<O> method() `	Called once at assembly time
@Outgoing Message<O> method() `	Called for every downstream request, sequentially
@Outgoing O method() `	Called for every downstream request, sequentially
@Outgoing CompletionStage<Message<O>> method() `	Called for every downstream request, sequentially (After the completion of the last returned CompletionStage)
@Outgoing CompletionStage<O> method() `	Called for every downstream request, , sequentially (After the completion of the last returned CompletionStage)
@Outgoing Uni<Message<O>> method() `	Called for every downstream request, sequentially (After the completion of the last returned Uni)
@Outgoing Uni<O> method() `	Called for every downstream request, , sequentially (After the completion of the last returned Uni)

Method signatures to consume data

Signature	Invocation time	Supported Acknowledgement Strategies
@Incoming void method(I p)	Called for every incoming payload (sequentially)	POST_PROCESSING, NONE, PRE_PROCESSING
@Incoming CompletionStage<?> method(Message<I> msg)	Called for every incoming message (sequentially)	MANUAL, NONE, PRE_PROCESSING
@Incoming CompletionStage<?> method(I p)	Called for every incoming payload (sequentially)	POST_PROCESSING, PRE_PROCESSING, NONE
@Incoming Uni<?> method(Message<I> msg)	Called for every incoming message (sequentially)	MANUAL, NONE, PRE_PROCESSING
@Incoming Uni<?> method(I p)	Called for every incoming payload (sequentially)	POST_PROCESSING, PRE_PROCESSING, NONE
@Incoming Subscriber<Message<I>> method()	Called once at assembly time	MANUAL, POST_PROCESSING, NONE, PRE_PROCESSING
@Incoming Subscriber<I> method()	Called once at assembly time	POST_PROCESSING, NONE, PRE_PROCESSING
@Incoming Flow.Subscriber<Message<I>> method()	Called once at assembly time	MANUAL, POST_PROCESSING, NONE, PRE_PROCESSING
@Incoming Flow.Subscriber<I> method()	Called once at assembly time	POST_PROCESSING, NONE, PRE_PROCESSING
@Incoming SubscriberBuilder<Message<I>, ?> method()	Called once at assembly time	MANUAL, POST_PROCESSING, NONE, PRE_PROCESSING
@Incoming SubscriberBuilder<I, ?> method()	Called once at assembly time	MANUAL, POST_PROCESSING, NONE, PRE_PROCESSING

Method signatures to process data

Signature	Invocation time	Supported Acknowledgement Strategies	Metadata Propagation
@Outgoing @Incoming Message<O> method(Message<I> msg)	Called for every incoming message (sequentially)	POST_PROCESSING (Smallrye only), MANUAL, NONE, PRE_PROCESSING	manual
@Outgoing @Incoming Message<O> method(I payload)	Called for every incoming message (sequentially)	POST_PROCESSING (Smallrye only), NONE, PRE_PROCESSING	automatic
@Outgoing @Incoming O method(I payload)	Called for every incoming payload (sequentially)	POST_PROCESSING, NONE, PRE_PROCESSING	automatic
@Outgoing @Incoming CompletionStage<Message<O>> method(Message<I> msg)	Called for every incoming message (sequentially)	MANUAL, NONE, PRE_PROCESSING	manual
@Outgoing @Incoming CompletionStage<O> method(I payload)	Called for every incoming payload (sequentially)	POST_PROCESSING, NONE, PRE_PROCESSING	automatic
@Outgoing @Incoming CompletionStage<Message<O>> method(I payload)	Called for every incoming payload (sequentially)	POST_PROCESSING (Smallrye only), NONE, PRE_PROCESSING	automatic
@Outgoing @Incoming Uni<Message<O>> method(Message<I> msg)	Called for every incoming message (sequentially)	MANUAL, NONE, PRE_PROCESSING	manual
@Outgoing @Incoming Uni<Message<O>> method(I payload)	Called for every incoming payload (sequentially)	POST_PROCESSING (Smallrye only), NONE, PRE_PROCESSING	automatic
@Outgoing @Incoming Uni<O> method(I payload)	Called for every incoming payload (sequentially)	POST_PROCESSING, NONE, PRE_PROCESSING	automatic
@Outgoing @Incoming Processor<Message<I>, Message<O>> method()	Called once at assembly time	MANUAL, PRE_PROCESSING, NONE	manual
@Outgoing @Incoming Processor<I, O> method()	Called once at assembly time	PRE_PROCESSING, NONE	not supported
@Outgoing @Incoming Flow.Processor<Message<I>, Message<O>> method()	Called once at assembly time	MANUAL, PRE_PROCESSING, NONE	manual
@Outgoing @Incoming Flow.Processor<I, O> method()	Called once at assembly time	PRE_PROCESSING, NONE	not supported
@Outgoing @Incoming ProcessorBuilder<Message<I>, Message<O>> method()	Called once at assembly time	MANUAL, PRE_PROCESSING, NONE	manual
@Outgoing @Incoming ProcessorBuilder<I, O> method()	Called once at assembly time	PRE_PROCESSING, NONE	not supported
@Outgoing @Incoming Publisher<Message<O>> method(Message<I> msg)	Called for every incoming message (sequentially)	MANUAL, PRE_PROCESSING, NONE	manual
@Outgoing @Incoming Publisher<O> method(I payload)	Called for every incoming payload (sequentially)	PRE_PROCESSING, POST_PROCESSING, NONE	automatic
@Outgoing @Incoming Multi<Message<O>> method(Message<I> msg)	Called for every incoming message (sequentially)	MANUAL, PRE_PROCESSING, NONE	manual
@Outgoing @Incoming Multi<O> method(I payload)	Called for every incoming payload (sequentially)	PRE_PROCESSING, POST_PROCESSING, NONE	automatic
@Outgoing @Incoming Flow.Publisher<Message<O>> method(Message<I> msg)	Called for every incoming message (sequentially)	MANUAL, PRE_PROCESSING, NONE	manual
@Outgoing @Incoming Flow.Publisher<O> method(I payload)	Called for every incoming payload (sequentially)	PRE_PROCESSING, POST_PROCESSING, NONE	automatic
@Outgoing @Incoming PublisherBuilder<Message<O>> method(Message<I> msg)	Called for every incoming message (sequentially)	MANUAL, PRE_PROCESSING, NONE	manual
@Outgoing @Incoming PublisherBuilder<O> method(I payload)	Called for every incoming payload (sequentially)	PRE_PROCESSING, POST_PROCESSING, NONE	automatic

Note that in additional to the MicroProfile Reactive Messaging specification, SmallRye Reactive Messaging supports the post-processing acknowledgment handling with automatic metadata propagation for the following signatures:

• @Outgoing @Incoming Message<O> method(I payload)
• @Outgoing @Incoming CompletionStage<Message<O>> method(I payload)
• @Outgoing @Incoming Uni<Message<O>> method(I payload)
• @Outgoing @Incoming Message<O> method(Message<I> payload) : For this signature, the post-processing acknowledgment handling is limited. It covers cases for nacking incoming messages on caught exceptions at the method body, acking incoming messages when outgoing message is skipped by returning null, and chaining acknowlegment from outgoing message to the incoming. However, if the incoming message has already been (n)acked, you will experience duplicate (n)acks.

Method signatures to manipulate streams

Signature	Invocation time	Supported Acknowledgement Strategies	Metadata Propagation
@Outgoing @Incoming Publisher<Message<O>> method(Publisher<Message<I>> pub)	Called once at assembly time	MANUAL, NONE, PRE_PROCESSING	manual
@Outgoing @Incoming Publisher<O> method(Publisher<I> pub)	Called once at assembly time	PRE_PROCESSING, NONE	not supported
@Outgoing @Incoming Multi<Message<O>> method(Multi<Message<I>> pub)	Called once at assembly time	MANUAL, NONE, PRE_PROCESSING	manual
@Outgoing @Incoming Multi<O> method(Multi<I> pub)	Called once at assembly time	PRE_PROCESSING, NONE	not supported
@Outgoing @Incoming Flow.Publisher<Message<O>> method(Flow.Publisher<Message<I>> pub)	Called once at assembly time	MANUAL, NONE, PRE_PROCESSING	manual
@Outgoing @Incoming Flow.Publisher<O> method(Flow.Publisher<I> pub)	Called once at assembly time	PRE_PROCESSING, NONE	not supported
@Outgoing @Incoming PublisherBuilder<Message<O>> method(PublisherBuilder<Message<I>> pub)	Called once at assembly time	MANUAL, NONE, PRE_PROCESSING	manual
@Outgoing @Incoming PublisherBuilder<O> method(PublisherBuilder<I> pub)	Called once at assembly time	NONE, PRE_PROCESSING	not supported

Important

When processing Message, it is often required to chain the incoming Message to enable post-processing acknowledgement and metadata propagation. Use the with (like withPayload) methods from the incoming message, so it copies the metadata and ack/nack methods. It returns a new Message with the right content.