Hi Behrooz,
the problem here is the finally block in code executed in your separate
thread. After first sent OutboundEvent you're closing the EventOutput
which means no more OutboundEvents can be sent to that client. Remove
the closing of EventOutput and all events should be sent to your client.
With this approach you need to handle event outputs closed by clients
and release the resources by yourself. The other possibility is to start
using SseBroadcaster ([1]) and store created EventOutputs in there (see
[2]). SseBroadcaster will take care of releasing resources of closed
event outputs for you. Then, in your separate thread, you should sent
new events via SseBroadcaster.broadcast method which delivers the events
to all connected clients.
[1]
https://jersey.java.net/apidocs/latest/jersey/org/glassfish/jersey/media/sse/SseBroadcaster.html
[2]
https://github.com/jersey/jersey/blob/master/examples/sse-item-store-webapp/src/main/java/org/glassfish/jersey/examples/sseitemstore/ItemStoreResource.java#L166
[3]
https://github.com/jersey/jersey/blob/master/examples/sse-item-store-webapp/src/main/java/org/glassfish/jersey/examples/sseitemstore/ItemStoreResource.java#L216
HTH,
Michal
On 29.04.2014, 20:14 , Behrooz Nobakht wrote:
>
> Hi,
>
> I’ve followed the documentation on SSE
> <https://jersey.java.net/documentation/latest/sse.html> to implement a
> RESTful resource in combination with a JavaScript client. Simplifying
> the code, at the level of Jersey resources, I have:
>
> |_at_GET
> @Produces(SseFeature.SERVER_SENT_EVENTS)
> @Path("out")
> public EventOutput get(
> @HeaderParam(SseFeature.LAST_EVENT_ID_HEADER)@DefaultValue("-1") String lastEventId) {
> final EventOutput output =new EventOutput();
> // publish an async mechanism to build the output in a separate thread
> return output;
> }
> |
>
> and in a separate thread, the event output is being built as:
>
> |OutboundEvent.Builder oeb =new OutboundEvent.Builder();
> List<MyPojo> events =// retrieve my pojos list
> oeb.name <http://oeb.name>("event");
> oeb.id <http://oeb.id>("someID");
> oeb.reconnectDelay(500);
> oeb.mediaType(MediaType.APPLICATION_JSON_TYPE);
> oeb.data(MyPojo.class,events);
> try {
> OutboundEvent event = oeb.build();
> output.write(event);
> logger.info <http://logger.info>("Flushed SSE event: {}", event);
> }catch (Exception x) {
> logger.error("Failed flushing SSE event: {}", x);
> }finally {
> try {
> output.close();
> }catch (Exception x2) {
> logger.error("Failed closing output: {}", x2);
> }
> }
> |
>
> and at the client side, I have a simple JavaScript code to use
> EventSource
> <https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events>
> as:
>
> |var source =new EventSource('//myserver/events/out');
> source.addEventListener('event',function(e) {
> var jsonData = JSON.parse(e.data);
> // use the jsonData
> },false);
> |
>
> The problem starts with the observation that only the first event is
> processed and all subsequent events remain in a “pending” state of
> HTTP request (using Chrome developer console).
>
> Investigating further shows indeed that the header Transfer-Encoding
> is set to “chunked”. By its own, I think this should not be a problem.
> However, there are a number of resources (such as this
> <http://stackoverflow.com/q/13590755/248082>, that
> <http://www.whatwg.org/specs/web-apps/current-work/multipage/comms.html#authoring-notes>,
> or even <https://github.com/http-kit/http-kit/issues/56>) suggest that
> Transfer-Encoding should be set to “identity” or even removed. Is this
> possibly from Jersey server side? I’m using Jersey with embedded Jetty
> HTTP container factory.
>
> It is also an interesting observation based on the above code that I
> see consecutive log lines saying “Flushed SSE Event …” but the client
> side remains pending and nothing happens further.
>
> I appreciate any feedback or solution to this issue as it seems not to
> be so documented or explored.
>
> Thanks in advance,
> Behrooz
>