JAX-RS 2.1 Reloaded

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DavidDelabassee@delabasseeOracleMay2017

JAX-RS2.1Reloaded


JAX-RS

•  StandardbasedRESTfulframework– JAX-RS2.0–JSR339(*)– JAX-RS2.1–JSR370– Jersey,JBossRESTEasy,Restlet,ApacheCXF,ApacheWink,IBMJAX-RS,…

•  JavaSEandJavaEE

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JavaAPIforRESTfulWebServices


SafeHarborStatementThefollowingisintendedtooutlineourgeneralproductdirec[on.Itisintendedforinforma[onpurposesonly,andmaynotbeincorporatedintoanycontract.Itisnotacommitmenttodeliveranymaterial,code,orfunc[onality,andshouldnotberelieduponinmakingpurchasingdecisions.Thedevelopment,release,and[mingofanyfeaturesorfunc[onalitydescribedforOracle’sproductsremainsatthesolediscre[onofOracle.

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Client-side

Confiden[al–OracleInternal/Restricted/HighlyRestricted 5


JAX-RSClientAPI

•  FluentAPI– ClientBuilderèClientèWebTargetè…èRequestbuildingèResponse

• Client– Clientsidecontainer– Customizable•  Keystore,sslContext,Timeout,etc.•  Setexecutorservice(2.1)– ClientBuilder.executorService(…);

javax.ws.rs.client.Clientinterface

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JAX-RSClientAPI

• WebTarget– TargetremoteURI– Buildfromaclient– path()+resolveTemplates(),queryParam(),matrixParam(),…

• Requestinvoca[onbuilder– BuildfromaWebTarget– acceptXXX(),cookie(),header(),cacheControl(),…– HTTPmethods


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JAX-RSClientAPI

• ClientInstanceèWebTargetèRequestInvoca[on


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Clientclient=ClientBuilder.newClient();List<Forecast>forecast=client.target("http://weath.er/cities").accept("application/json").header("Foo","bar").get(newGenericType<List<Forecast>>(){});


JAX-RSClientAPI

•  Synchronousinvoker

• Asynchronousinvoker

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Stringcity=client.target("http://locati.on/api").queryParam("city","Paris").request().get(String.class);

Future<String>future=client.target("http://locati.on/api")….request().async().get(String.class);


JAX-RSClientAPIAsynchronousinvoca:on

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Future<String>future=client.target("http://locati.on/api")…

.request().async().get(String.class);Stringcity=future.get();



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.request().async().get(String.class);

try{

Stringcity=future.get(5,TimeUnit.SECONDS);

}catch(TimeoutExceptiontimeout){…}



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.request().async().get(String.class);

while(!future.isDone()){//responsehasn'tbeenreceivedyet…}

Stringcity=f.get();…

//SetClientProperties.CONNECT_TIMEOUT&READ_TIMEOUT


JAX-RSClientAPI

•  Invoca[onCallbackInterface– javax.ws.rs.client.Invoca[onCallback<RESPONSE>

• Willreceivetheasynchronousprocessingeventsfromaninvoca[on– completed(RESPONSEresponse)– failed(Throwablethrowable)

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Asynchronousinvoca:on


JAX-RSClientAPI

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Invoca:onCallback…WebTargetmyResource=client.target("http://examp.le/api/read");Future<Customer>future=myResource.request(MediaType.TEXT_PLAIN).async().get(newInvocationCallback<Customer>(){

@Overridepublicvoidcompleted(Customercustomer){//dosomethingwiththegivencustomer}

@Overridepublicvoidfailed(Throwablethrowable){//Oops!}

});


TheTravelService


TheTravelServicedestination.path("recommendedDestinations").request().header("Rx-User","...").async().get(newInvocationCallback<List<Destination>>(){@Overridepublicvoidcompleted(finalList<Destination>recommended){finalCountDownLatchinnerLatch=newCountDownLatch(recommended.size());finalMap<String,Forecast>forecasts=Collections.synchronizedMap(newHashMap<>());for(finalDestinationdest:recommended){forecast.resolveTemplate("dest",dest.getDestination()).request().async().get(newInvocationCallback<Forecast>(){@Overridepublicvoidcompleted(finalForecastforecast){forecasts.put(dest.getDestination(),forecast);innerLatch.countDown();}


JAX-RS2.0

@Overridepublicvoidfailed(finalThrowablethrowable){innerLatch.countDown();}});}

try{if(!innerLatch.await(10,TimeUnit.SECONDS)){//timeout}}catch(finalInterruptedExceptione){//Ooops,interrupted!}

//Continuewithprocessing…}

@Overridepublicvoidfailed(finalThrowablethrowable){//Recommendationerror}});


JAX-RS2.1

//JAX-RS2.1CompletionStage<Response>csResponse=ClientBuilder.newClient().target("http://example.com/api").request().rx().get();

Future<Response>fResponse=ClientBuilder.newClient().target("http://example.com/api").request().async().get();

Responseresponse=ClientBuilder.newClient().target("http://example.com/api").request().get();


Comple[onStageinterface

•  “Astageofapossiblyasynchronouscomputa[on,thatperformsanac:onorcomputesavalue.Ontermina[onastagemayinturntriggerotherdependentstages.”• Astage'sexecu[onmaybetriggeredbycomple[onofstage(s)– 1“then”,2“combine”or1of2“either”

• Doesthecomputa[ontakesanargumentandreturnsaresult?– “apply”Func[on,“accept”Consumeror“run”Runnable

•  ...

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hrps://docs.oracle.com/javase/8/docs/api/java/u[l/concurrent/Comple[onStage.html


JAX-RS2.1

CompletionStage<Number>csp=client.target("price/{destination}").resolveTemplate("destination","Paris").request().rx().get(Number.class);CompletionStage<String>csf=client.target("forecast/{destination}").resolveTemplate("destination","Paris").request().rx().get(String.class);newCs=cscsp.thenCombine(csf,(price,forecast)->reserveIfAfforadble(price,forecast));


Demo

•  TheTravelService

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hrps://github.com/jersey/jersey/tree/master/examples/rx-client-webapp


JAX-RS2.1Reac[veClientAPI

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Sync Async RXPerformanceandscalability ✗✗ ✔ ✔Easytodevelopandmaintain ✔ ✗ ✔

…complexworkflow ✗ ✗ ✔…errorhandling ✗ ✗ ✔

LeveragenewJavaSEfeature ✗ ✗ ✔


JAX-RSClientAPI

• RESTClientSidecontainer•  Synchronous– javax.ws.rs.client.SyncInvokerinterface– Defaultinvoker

• Asynchronous– javax.ws.rs.client.AsyncInvokerinterface– async()invoker– Mightblock!– Invoca[onCallback

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Summary


JAX-RS2.1Reac[veClientAPI• NewAsyncReac[veinvoker– javax.ws.rs.client.RxInvokerinterface

• Reac[veInvokerProviders– JavaSE8Comple[onStage– Jersey•  RxJava-rx.Observable•  RxJava2-io.reac[vex.Flowable•  Guava–ListenableFuture

• ClientBuilder.executorService(…);

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Server-side



Server-side@Path("/Item")publicclassItemResource{@Path("{id}")@Produces(MediaType.APPLICATION_JSON)publicItemResourcegetItemResource(@PathParam("id")Stringid){returnItemResource.getInstance(id);}@POST@Consumes(MediaType.APPLICATION_XML)@Produces(MediaType.APPLICATION_JSON)publicResponsecreateItem(@QueryParam("name")Stringname){//...returnResponse.status(Status.OK).entity(…).build();}}


Server-sideAsync@Path("async/longRunning")publicclassItemResource{

@GETpublicvoidlongRunningOp(@SuspendedAsyncResponsear){

mes.execute(newRunnable(){@Overridepublicvoidrun(){try{//longrunningcomputation...ar.resume(Response.ok(...).build());}catch(InterruptedExceptionex){//Ooops!}}});...


Server-sideAsync

• Asynchronousresponse– Providesmeansforasynchronousserversideresponseprocessing– Injectablevia@Suspended– Boundtotherequest

• Requestprocessing– Suspend– Resume– Configure– Cancel

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AsyncResponseinterface


Server-sideAsync

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Newin2.1@Path("/async/longRunning")publicclassItemResource{

@GETpublicCompletionStage<String>longRunningOp(){CompletableFuture<String>cs=newCompletableFuture<>();executor.submit(newRunnable(){

publicvoidrun(){executeLongRunningOp();cs.complete("Helloasyncworld!");}});returncs;}...}


Server-sideAsync

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Client Server

@Suspended

AsyncResponse.resume(…)

Longrunningopera[on…

Request

Response


LongrunningRESTopera[ons

è POST...longrunningopera[on...ç ‘201Created’+Loca[on

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è POSTç ‘202Accepted’+TempLoca[on

è GETTempLoca[onç ‘200OK’(+ETA)…è GETTempLoca[onç ‘303SeeOther’+FinalLoca[on


Server-sentEvents

• Persistent,one-waycommunica[onchannel•  Textprotocol,specialmediatype"text/event-stream"•  Servercansendmul[plemessages(events)toaclient• Cancontainid,name,commentretryinterval•  Supportedinallmodernbrowsers

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JAX-RS2.1

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SSE

•  SseEvent– ID,Name,Comment,…

• OutboundSseEvent– Server-siderepresenta[onofaServer-sentevent– OutboundSseEvent.Builder()

•  InboundSseEvent– Client-siderepresenta[onofaServer-sentevent


JAX-RS2.1

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SSE–Serverside

•  SseEventSink– OutboundServer-SentEventsstream– SseBroadcaster

@GET@Path("sse")@Produces(MediaType.SERVER_SENT_EVENTS)publicvoideventStream(@ContextSseEventSinkeventSink,@ContextSSEsse){...eventSink.send(sse.newEvent("anevent"));eventSink.send(sse.newEvent("anotherevent"));...eventSink.close();}


JAX-RS2.1

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SSE–Clientside

•  SseEventSource– ClientforprocessingincomingServer-SentEvents

SseEventSourcees=SseEventSource.target(SSE_target).reconnectingEvery(5,SECONDS).build();es.register(System.out::println);//InboundSseEventconsumeres.register(...);//Throwableconsumeres.open();...es.close();


Wrap-up



JAX-RS

•  JavaAPIforRESTfulWebServices– JAX-RS2.0–JSR339

•  StandardbasedRESTfulframework– Server-sideandclient-side– JavaSEandJavaEE– Jersey,JBossRESTEasy,Restlet,ApacheCXF,ApacheWink,IBMJAX-RS,…

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JAX-RS2.1–JSR370

• Reac[veClientAPI•  Server-sentEventssupport•  JSON-B&JSON-P1.1support• Misc.– Providersordering– PassingincomingrequestLocaletoBV– SerableClientexecutorservice– ReturnaninstanceofComple[onStage<T>– …hrps://github.com/jax-rs/api/labels/2.1-candidate(tbc)

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• Non-blockingIOsupport• MakeJAXBop[onal


JavaEE8

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BeanValida:on

CDI2.0

JSON-B1.0

Security1.0

BV2.0

JSF2.3

Servlet4.0

JSON-P1.1

JAX-RS2.1 Reac[veclientAPI,Server-sentevents,…

HTTP/2,serverpush,…

Java<->JSONbinding

UpdatestoJSONstandards,JSONCollectors,…

Asyncevent,eventpriority,SEsupport,…

EmbraceJavaSE8,newconstraints

ImprovedCDI,WebSocket,SE8integra[on,…

StandardizedIden[tyStore,Authen[ca[on,SecurityContext


JavaEE8• Workinprogress– FinalRelease-Summer2017(plan)

• OpenSourceReferenceImplementa[ons– hrps://github.com/javaee– hrps://github.com/jersey

• Contribute!– AdoptAJSR

•  Staytuned…– hrps://blogs.oracle.com/theaquarium/

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Resources

•  JAX-RSspecifica[on– hrps://github.com/jax-rs/api

•  Jersey– hrps://github.com/jersey

•  Jersey–AsynchronousServicesandClients– hrps://jersey.github.io/documenta[on/latest/user-guide.html#async

• Comple[onStageJavadoc– hrps://docs.oracle.com/javase/8/docs/api/java/u[l/concurrent/Comple[onStage.html

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Q&A


JAX-RS 2.1 Reloaded

Software

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