Package io.smallrye.reactive.messaging

Interface MutinyEmitter<T>

Type Parameters:
T - type of payload
All Superinterfaces:
EmitterType
public interface MutinyEmitter<T> extends EmitterType
Interface used to feed a channel from an imperative piece of code.

Instances are injected using: 

 @Inject
 @Channel("my-channel")
 MutinyEmitter<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 `MutinyEmitter` when a downstream subscriber hasn't requested more messages.

  • Method Summary

    Modifier and Type
    Method
    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
    hasRequests()
     
    boolean
    isCancelled()
     
    <M extends Message<? extends T>>
    void
    send(M msg)
    Deprecated.
    use {sendMessageAndForget(Message)}
    io.smallrye.mutiny.Uni<Void>
    send(T payload)
    Sends a payload to the channel.
    void
    sendAndAwait(T payload)
    Sends a payload to the channel.
    io.smallrye.mutiny.subscription.Cancellable
    sendAndForget(T payload)
    Sends a payload to the channel without waiting for acknowledgement.
    <M extends Message<? extends T>>
    io.smallrye.mutiny.Uni<Void>
    sendMessage(M msg)
    Sends a message to the channel.
    <M extends Message<? extends T>>
    void
    sendMessageAndAwait(M msg)
    Sends a message to the channel.
    <M extends Message<? extends T>>
    io.smallrye.mutiny.subscription.Cancellable
    sendMessageAndForget(M msg)
    Sends a message to the channel without waiting for acknowledgement.

  • Method Details

    • send

      @CheckReturnValue io.smallrye.mutiny.Uni<Void> send(T payload)
      Sends a payload to the channel.

      A Message object will be created to hold the payload and the returned Uni can be subscribed to for triggering the send. When subscribed, a null item will be passed to the Uni when the Message is acknowledged. If the Message is never acknowledged, then the Uni will never be completed.

      The Message will not be sent to the channel until the Uni has been subscribed to: 

       emitter.send("a").subscribe().with(x -> {
 });
      Parameters:
      payload - the thing to send, must not be null
      Returns:
      the Uni, that requires subscription to send the Message.
      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.

    • sendAndAwait

      void sendAndAwait(T payload)
      Sends a payload to the channel.

      A Message object will be created to hold the payload.

      Execution will block waiting for the resulting Message to be acknowledged before returning.

      Parameters:
      payload - the thing 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.

    • sendAndForget

      io.smallrye.mutiny.subscription.Cancellable sendAndForget(T payload)
      Sends a payload to the channel without waiting for acknowledgement.

      A Message object will be created to hold the payload.

      Parameters:
      payload - the thing to send, must not be null
      Returns:
      the Cancellable from the subscribed Uni.
      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

      @Deprecated <M extends Message<? extends T>> void send(M msg)
      Deprecated.
      use {sendMessageAndForget(Message)}
      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.

    • sendMessage

      <M extends Message<? extends T>> io.smallrye.mutiny.Uni<Void> sendMessage(M msg)
      Sends a message to the channel.
      Type Parameters:
      M - the Message type
      Parameters:
      msg - the Message to send, must not be null
      Returns:
      the Uni, that requires subscription to send the Message.
      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.

    • sendMessageAndAwait

      <M extends Message<? extends T>> void sendMessageAndAwait(M msg)
      Sends a message to the channel. Execution will block waiting for the resulting Message to be acknowledged before returning.
      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.

    • sendMessageAndForget

      <M extends Message<? extends T>> io.smallrye.mutiny.subscription.Cancellable sendMessageAndForget(M msg)
      Sends a message to the channel without waiting for acknowledgement.
      Type Parameters:
      M - the Message type
      Parameters:
      msg - the Message to send, must not be null
      Returns:
      the Cancellable from the subscribed Uni.
      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.

    • 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.

    • hasRequests

      boolean hasRequests()
      Returns:
      true if one or more subscribers request messages from the corresponding channel where the emitter connects to, return false otherwise.