javax.ws.rs.sse

Interface SseBroadcaster

All Superinterfaces:

AutoCloseable, Flow.Publisher<OutboundSseEvent>

public interface SseBroadcaster
extends AutoCloseable, Flow.Publisher<OutboundSseEvent>

Server-Sent events broadcasting facility.

Server broadcaster can be used to manage multiple server sinks. It enables sending events to all registered event outputs and provides facility to effectively handle exceptions and closures of individual registered event outputs.

Instance of this interface is thread safe, meaning that it can be shared and its method invoked from different threads without causing inconsistent internal state.

Since:

2.1

Author:

Marek Potociar

Method Summary

Modifier and Type	Method and Description
void	broadcast(OutboundSseEvent event) Publish an SSE event to all subscribed SseEventSink instances.
void	close() Close the broadcaster and all subscribed SseEventSink instances.
void	onClose(Consumer<Flow.Subscriber<? super OutboundSseEvent>> onClose) Register a listener, which will be called when the SSE event output has been closed (either by client closing the connection or by calling SseEventSink.close() on the server side.
void	onError(BiConsumer<Flow.Subscriber<? super OutboundSseEvent>,Throwable> onError) Register a listener, which will be called when an exception was thrown by a given SSE event output when trying to write to it or close it.
void	subscribe(Flow.Subscriber<? super OutboundSseEvent> subscriber) Subscribe OutboundSseEvent subscriber (i.e.

Method Detail

onError

void onError(BiConsumer<Flow.Subscriber<? super OutboundSseEvent>,Throwable> onError)

Register a listener, which will be called when an exception was thrown by a given SSE event output when trying to write to it or close it.

This operation is potentially slow, especially if large number of listeners get registered in the broadcaster. The SseBroadcaster implementation is optimized to efficiently handle small amounts of concurrent listener registrations and removals and large amounts of registered listener notifications.

Parameters:

onError - bi-consumer, taking two parameters: SseEventSink, which is the source of the error and the actual Throwable instance.

onClose

void onClose(Consumer<Flow.Subscriber<? super OutboundSseEvent>> onClose)

Register a listener, which will be called when the SSE event output has been closed (either by client closing the connection or by calling SseEventSink.close() on the server side.

This operation is potentially slow, especially if large number of listeners get registered in the broadcaster. The SseBroadcaster implementation is optimized to efficiently handle small amounts of concurrent listener registrations and removals and large amounts of registered listener notifications.

Parameters:

onClose - consumer taking single parameter, a SseEventSink, which was closed.

subscribe

void subscribe(Flow.Subscriber<? super OutboundSseEvent> subscriber)

Subscribe OutboundSseEvent subscriber (i.e. SseEventSink) to this SseBroadcaster instance.

Specified by:

subscribe in interface Flow.Publisher<OutboundSseEvent>

Parameters:

subscriber - Subscriber<OutboundSseEvent> to register.

broadcast

void broadcast(OutboundSseEvent event)

Publish an SSE event to all subscribed SseEventSink instances.

Parameters:

event - SSE event to be published.

close

void close()

Close the broadcaster and all subscribed SseEventSink instances.

Subsequent calls have no effect and are ignored. Once the SseBroadcaster is closed, invoking any other method on the broadcaster instance would result in an IllegalStateException being thrown.

Specified by:

close in interface AutoCloseable