RxJava rx.Observable support
Introduction
RxJava 1 rx.Observable is supported on the client and the server side starting from CXF 3.2.0.
org.apache.cxf/cxf-rt-rs-extension-rx/3.2.0 dependency is required.
Client
import org.apache.cxf.jaxrs.rx.client.ObservableRxInvoker; import org.apache.cxf.jaxrs.rx.client.ObservableRxInvokerProvider; @Test public void testObservableWithWebClient() throws Exception { String address = "http://localhost:" + PORT + "/observable/textAsync"; WebClient wc = WebClient.create(address, Collections.singletonList(new ObservableRxInvokerProvider())); Observable<String> obs = wc.accept("text/plain") .rx(ObservableRxInvoker.class) .get(String.class); obs.map(s -> { return s + s; }); Thread.sleep(3000); obs.subscribe(s -> assertDuplicateResponse(s)); } @Test public void testObservableJaxrs21With404Response() throws Exception { String address = "http://localhost:" + PORT + "/observable/textAsync404"; Invocation.Builder b = ClientBuilder.newClient().register(new ObservableRxInvokerProvider()) .target(address).request(); b.rx(ObservableRxInvoker.class).get(String.class).subscribe( s -> { fail("Exception expected"); }, t -> validateT((ExecutionException)t)); } private void validateT(ExecutionException t) { assertTrue(t.getCause() instanceof NotFoundException); } private void assertDuplicateResponse(String s) { assertEquals("Hello, world!Hello, world!", s); }
Server
As a method return value
One simply returns an Observable from the method and the runtime will make sure the response is finalized once the Observable flow is complete.
The only requirement is that one has to register a custom JAX-RS invoker, org.apache.cxf.jaxrs.rx.server.ObservableInvoker. It does all the default JAXRSInvoker does and only checks if Observable is returned - if yes then it links it internally with the JAX-RS AsyncResponse.
Combining with AsyncResponse
import org.apache.cxf.jaxrs.rx.server.ListAsyncSubscriber; import org.apache.cxf.jaxrs.rx.server.JsonStreamingAsyncSubscriber; @GET @Produces("application/json") @Path("textJsonImplicitListAsync") public void getJsonImplicitListAsync(@Suspended AsyncResponse ar) { final HelloWorldBean bean1 = new HelloWorldBean(); final HelloWorldBean bean2 = new HelloWorldBean("Ciao"); new Thread(new Runnable() { public void run() { try { Thread.sleep(2000); } catch (InterruptedException ex) { // ignore } Observable.just(bean1, bean2).subscribe(new ListAsyncSubscriber<HelloWorldBean>(ar)); } }).start(); } // return a JSON array, write to the output stream as soon as the next JSON object becomes available @GET @Produces("application/json") @Path("textJsonImplicitListAsyncStream") public void getJsonImplicitListStreamingAsync(@Suspended AsyncResponse ar) { Observable.just("Hello", "Ciao") .map(s -> new HelloWorldBean(s)) .subscribeOn(Schedulers.computation()) .subscribe(new JsonStreamingAsyncSubscriber<HelloWorldBean>(ar)); }