Package ratpack.sse

Class ServerSentEvents

java.lang.Object

ratpack.sse.ServerSentEvents

All Implemented Interfaces:

Renderable

public class ServerSentEvents
extends java.lang.Object
implements Renderable

A renderable object for streaming server side events.

A renderer for this type is implicitly provided by Ratpack core.

Example usage:

 import org.reactivestreams.Publisher;
 import ratpack.http.client.ReceivedResponse;
 import ratpack.sse.ServerSentEvent;
 import ratpack.sse.ServerSentEvents;
 import ratpack.test.embed.EmbeddedApp;

 import java.time.Duration;
 import java.util.Arrays;
 import java.util.Objects;

 import static ratpack.stream.Streams.periodically;

 import static java.util.stream.Collectors.joining;

 import static org.junit.Assert.assertEquals;

 public class Example {
   public static void main(String[] args) throws Exception {
     EmbeddedApp.fromHandler(context -> {
       Publisher<ServerSentEvent> stream = periodically(context, Duration.ofMillis(5), i ->
         i < 5 ? ServerSentEvent.builder().id(i.toString()).event("counter").data("event " + i).build() : null
       );

       context.render(ServerSentEvents.builder().build(stream));
     }).test(httpClient -> {
       ReceivedResponse response = httpClient.get();
       assertEquals("text/event-stream;charset=UTF-8", response.getHeaders().get("Content-Type"));

       String expectedOutput = Arrays.asList(0, 1, 2, 3, 4)
         .stream()
         .map(i -> "id: " + i + "\nevent: counter\ndata: event " + i + "\n")
         .collect(joining("\n"))
         + "\n";

       assertEquals(expectedOutput, response.getBody().getText());
     });
   }
 }
 

See Also:

Wikipedia - Using server-sent events, MDN - Using server-sent events, builder()

Method Summary

Modifier and Type	Method	Description
static ServerSentEventsBuilder	builder()	Creates a builder for an event stream.
Publisher<? extends Event<?>>	getPublisher()	Deprecated. since 1.10 with no replacement
void	render(Context context)	Render this object to the response.
static <T> ServerSentEvents	serverSentEvents(Publisher<T> publisher, ratpack.func.Action<? super Event<T>> action)	Deprecated. since 1.10 - use builder()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

builder

public static ServerSentEventsBuilder builder()

Creates a builder for an event stream.

Returns:

a builder for an event stream

serverSentEvents

@Deprecated
public static <T> ServerSentEvents serverSentEvents(Publisher<T> publisher,
                                                    ratpack.func.Action<? super Event<T>> action)

Deprecated.

since 1.10 - use builder()

Deprecated.

getPublisher

@Deprecated
@Nullable
public Publisher<? extends Event<?>> getPublisher()

Deprecated.

since 1.10 with no replacement

Deprecated.

render

public void render(Context context)
            throws java.lang.Exception

Render this object to the response.

Specified by:

render in interface Renderable

Parameters:

context - the request handling context

Throws:

java.lang.Exception - any