Flux + Server Side Events

Question

Im familiar with Spring Flux + SSE, tried to write some code that stream data.

Two issues here:

1. When Im making request in Chrome It does not closing connection for a some time (loading circle is spinning), but Im using regular Flux.fromIterable that emmits complete signal at the end of array.

2. It closes commection for a some time (about 1 minute). Probably its timeout somewhere. Response should be cloused only when OnComplete event fires.

   @Controller("/")
   @Validated
   public class HelloController {
   
       @Produces(MediaType.TEXT_EVENT_STREAM) // add 'application/stream+json'
       @Get("/hello/{name}")
       public Flux<Hello> hello(@NotBlank String name) {
   
           List<Hello> list = new ArrayList<>();
   
           list.add(new Hello("test1", 1));
           list.add(new Hello("test2", 2));
   
           return Flux.fromIterable(list).doOnComplete(() -> {
               System.out.println("response should be closed here!");
           });
       }
   }
   

-Also please add support for the application/stream+json content-type

-And support server side events for a client via Flux.

Answer 1

As far as I am aware the content type application/stream+json is not an official media type. There is a draft attempting to registering this type but it relates to activity streams https://tools.ietf.org/id/draft-snell-activity-streams-type-01.html

The test https://github.com/micronaut-projects/micronaut-core/commit/b71f63aa8f2b2f00bdcbc25e60d9112321d8f003#diff-29dce542bb2e6326257895b376220c1aR16

Demonstrates your use case implemented with MediaType.APPLICATION_JSON_STREAM which is of type application/x-json-stream

As for why chrome keeps spinning this is because Micronaut implements keep alive and keeps the connection alive to satisfy further requests