[CON7983] JAX-RS 2.1 for Java EE 8

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3 [CON7983] JAX-RS 2.1 for Java EE 8 Ed Burns Pavel Bucek Oracle September, 2016

4 Safe Harbor Statement The preceding is intended to outline our general product direcuon. It is intended for informauon purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or funcuonality, and should not be relied upon in making purchasing decisions. The development, release, and Uming of any features or funcuonality described for Oracle s products remains at the sole discreuon of Oracle. 4

5 Speaker Bios Ed Burns Pavel Bucek Servlet and JSF co-spec lead Frequent internauonal conference speaker Author of four Enterprise Java related books from McGraw-Hill Java API for WebSocket spec lead Long Ume Jersey developer and implementauon lead REST expert 5

6 Program Agenda JAX-RS in Java EE 8 ReacUve API, NIO Improvements Server sent events Java EE integrauon, Circuit breakers, HTTP/2 Roadmap, Q&A ConfidenUal Oracle Internal/Restricted/Highly Restricted 6 E

7 JAX-RS in Java EE 8 ExisUng proposal of scope remains unchanged We will fold in and make adjustments to beher align JAX-RS with Java EE 8 focus on microservices, containers, and other key aspects of the Java EE 8 update. Jersey will conunue to be the reference implementauon GlassFish will conunue to be the release vehicle 7 E

8 Why JAX-RS is important If you are doing REST in Java, you are likely doing JAX-RS Most popular alternauve is Spring RestController Several popular frameworks depend on or leverage Jersey Dropwizard Spring Boot Apache Camel Ehcache Server MulUple implementauons Jersey (Reference ImplementaUon) RESTEasy Apache CXF 8 E

9 Brief Aside Cavium Java on ARM64 Servers and Scaling with Many Core Processors [CON8256] Tuesday, Sep 20, 4:00 p.m. - 5:00 p.m. Hilton - Golden Gate 6/7/8 9 E

10 JAX-RS history JAX-RS 1.1 JSR 311, Java EE 6, 2009 Java API for REST services, POJO based, HTTP centric, Container independent, JAX-RS 2.0 JSR 339, Java EE 7, 2014 REST Client API, Filters and interceptors, Async processing, Bean validauon, JSON-P, JAX-RS 2.1 JSR-370, Java EE 8, 2017 Non-blocking IO, ReacUve clients, Server Sent Events 10 E

11 InnovaUon and StandardizaUon Jersey and other sources influence JAX-RS Jersey 1.x 2.x 3.x Client ReacUve API? Filters SSE JAX-RS x 11 E

12 InnovaUon and StandardizaUon Jersey and other sources influence JAX-RS Jersey JAX-RS 1.0 client filters E

13 InnovaUon and StandardizaUon Jersey and other sources influence JAX-RS Jersey JAX-RS 2.0 reactive SSE... client filters 13 E

14 InnovaUon and StandardizaUon Jersey and other sources influence JAX-RS Jersey JAX-RS client filters reactive SSE 14 E

15 ReacUve Client API - Future<T> JAX-RS E

16 ReacUve API Copyright 2016, Oracle and/or its affiliates. All rights reserved. 16

17 ReacUve Client API - InvocaUonCallback<T> JAX-RS E

18 ReacUve Client API - CompletableFuture<T> JAX-RS 2.1 Java 8 improved Future<T> CompletableFuture<T> is an implementauon of CompleUonStage<T> Lots and lots of features (~38 methods) ComposiUon, callbacks, thenapply, thenaccept, thenrun, thencombine,... Ideal for sequenual reacuve invocauon Get responses from s1 and s2, combine results, call s3 and print out response 18 E

19 ReacUve Client API - CompletableFuture<T> JAX-RS 2.1 CompletableFuture vs Invoca@onCallback 19 P

20 ReacUve Client API - CompletableFuture<T> JAX-RS P

21 ReacUve Client API JAX-RS 2.1 Client RX API is extensible RxInvoker<T> InvocaUon.Builder <T extends RxInvoker> T rx(class<t> clazz) Guava ListenableFuture RxJava Observable SpecificaUon itself most likely won t require support for anything else than CompletableFuture<T>, but implementauons CAN provide support for whatever they like. 21 E

22 ReacUve Client API in Jersey Nice example of implementauon first approach hhps://github.com/jersey/jersey/tree/master/ext/rx (similar to SSE, which was also implemented in Jersey.. Long Ume ago. In this galaxy.) 22 E

23 TradiUonal Synchronous Request/Response public class StoreResource public List<PromotedProduct> getwishlistedpromotions() { List<PromotedProduct> result = new LinkedList<>(); for (String productid : usermanagementservice.getwishlistedproducts(userid)) { List<Promotion> promotions = promotionservice.getpromotionsfor(productid); Product product = productcatalog.getdetail(productid); } result.add(new PromotedProduct(promotions, product)); } return result; } ConfidenUal Oracle Internal/Restricted/Highly Restricted 23 E

24 ProgrammaUc (Semi)ReacUve public class StoreResource String userid; private vola@le boolean done = false; private final TransferQueue<PromotedProduct> events = @Produces("text/event-stream") public void final AsyncResponse asyncresponse) { asyncresponse.resume(new StreamingOutput() public void write(outputstream out) { while (!done) { PromotedProduct product = events.take(); out.write(product.tossejson()); } } }); } CompletableFuture<ServletInputStream> productidstreamfuture = usermanagementservice.getasyncwishlistedproducts(userid); productidstreamfuture.whencomplete((servletinput, excepuon) -> { if (excepuon!= null) { asyncresponse.resume(cause); } servletinput.setreadlistener(new ReadListener public void ondataavailable() { try { do { OpUonal<String> productidopuonal = readnextproductid(input); productidopuonal.ifpresent(this::processproductid); } while (input.isready()); } catch (IOExcepUon e) { handleexcepuon(e); } public void onalldataread() { done = true; public void onerror(throwable t) { handleexcepuon(t); } }); }); } private processproductid(string productid) { CompletableFuture<List<PromoUon>> promouonsfuture = promouonservice.getasyncpromouonsfor(productid); } CompletableFuture<Product> productfuture = productcatalog.getdetail(productid); promouonsfuture.thencombine(productfuture, (promouons, product) -> { events.transfer(new PromotedProduct(promoUons, product)) }).excepuonally(this::handleexcepuon); // more methods ConfidenUal Oracle Internal/Restricted/Highly Restricted 24 E

25 DeclaraUve ReacUve public class StoreResource String public PromotedProduct List<Promotion> Product product) { return new PromotedProduct(promotions, product); } getpromouons Product ID public List<Promotion> getpromotions(@result("productid") String productid) { return promotionservice.getpromotionsfor(productid); } PromoUons??? Product Detail public Product getproductdetail(@result("productid") String productid) { return productcatalog.getdetail(productid); public EventSource<String> getproductidevents() { return usermanagementservice.getwishlistedproducts(userid); } Promoted Product getwishlistedpromouon Emit as SSE Event ConfidenUal Oracle Internal/Restricted/Highly Restricted 25 E

26 Non-blocking I/O Async / reacuve is not non-blocking! Async processing usually just fires another thread, which is BLOCKED unul it does what it needs JAX-RS supports Async processing since 2.0 (Since Servlet 3.0) Server side suspend current thread, do the work in different one, resume the response. Client side future / callback 26 P

27 Non-blocking I/O JAX-RS defines several APIs where standard Java Input/Output Streams are used because of that, any JAX-RS implementauon is blocking by design MessageBodyReader and MessageBodyWriter will need to be changed It s not clear how yet Several opuons, from new MBR/MBW interfaces, to something similar to Servlet input/output stream 27 P

28 Non-blocking I/O JAX-RS 2.1 milestone 1 JAX-RS API NIO Proposal NioInvoker NioWriterHandler NioOutputStream extends OutputStream Work in progress 28 P

29 Server Sent Events JAX-RS 2.1 Special Media Type text/event-stream W3 standard, part of HTML 5 Server to Client communicauon channel Text protocol, separate messages with some metadata event, data, id, retry 29 P

30 Server Sent Events JAX-RS 2.1 Client GET /sse Accept: text/event-stream Server HTTP/ OK Content-Type: text/event-stream Date: Tue, 06 Sep :39:30 GMT Transfer-Encoding: chunked event: custom-message data: JAX-RS 2.1 event: custom-message data: test event: custom-message data: JavaOne P

31 Server Sent Events JAX-RS 2.1 Client GET /sse Accept: text/event-stream Server HTTP/ OK Content-Type: text/event-stream Date: Tue, 06 Sep :39:30 GMT Transfer-Encoding: chunked event: custom-message data: JAX-RS 2.1 event: custom-message data: test event: custom-message data: JavaOne

32 Server Sent Events Use ExecutorService instead 32 P

33 Server Sent Events 33 P

34 Server Sent Events 34 P

35 Server Sent Events JAX-RS 2.1 Even beher with HTTP/2 Shared TCP connecuon one stream can be used as a SSE channel (server to client) other one as a client to server This setup is starung to be comparable to WebSocket But sull not the same Web Protocols for Java Developers [CON4156] Embarcadero@Parc55, Thu 11:30am 35 E

36 IntegraUons with other SpecificaUons Copyright 2016, Oracle and/or its affiliates. All rights reserved. 36 P

37 IntegraUon with JSON-B JSR 367 Java API for JSON Binding New specificauon to be introduced in Java EE 8 Seamless integrauon, similar to what JAX-RS provides for JAX-B Official support for applicauon/json Configurable binding properues Formang, encoding, naming and ordering strategies, adapters, 37 P

38 Improved CDI integrauon JAX-RS 2.1 Improved behavior of resources, which are also CDI beans Constructor selecuon Generic param ) String param Bootstrapping and running outside of Java EE Standalone Java SE ApplicaUon ImplementaUon perspecuve It would be really nice to have the opuon to select runume DI framework HK2 vs CDI vs Guice vs 38 P

39 Java EE Security API JAX-RS 2.0 already contains support for Security Inject SecurityContext AuthenUcaUon scheme User principal @RolesAllowed Security specificauon is going to add OAuth and OpenID Connect support 39 P

40 IntegraUon with Java EE ConfiguraUon specificauon Standard ConfiguraUon API Externalized configurauon Support for various property formats, Layering, Overrides Support for muluple configurauon sources Mutable and immutable configurauon properues ConfiguraUon for Java EE 8 and the Cloud [CON7979] Wednesday, 11:30 40 P

41 IntegraUon with Java EE ConfiguraUon specificauon 41 P

42 Circuit breakers success or fail Closed fail count reached Open success fail Reset Umeout Half Open 42 E

43 Circuit breakers Generic way to deal with failures in remote service invocauon process ProtecUng system resources by monitoring calls to remote service If some certain number of failures is reached, no further calls are made and the error is returned immediately When a circuit is open, error supplier might provide replacement answer Could be completely different (empty) answer, or cached value from previous successful invocauon Several HTTP properues which could trigger failure TCP level: connect error, connect Umeout, connecuon Umeout,.. HTTP level: status code, 43 E

44 Circuit breakers JAX-RS ProgrammaUc approach change in the JAX-RS client API DeclaraUve approach classes to the Client Something else Configurable SLA (success/fail evaluauon and threshold) per external service Expert group will decide whether or how is this going to be included 44 E

45 HTTP/2 and JAX-RS Does JAX-RS needs to be updated to work on top of HTTP/2? HTTP/2 is sull request/response New features are mostly implemented in lower layers Will be JAX-RS API faster on HTTP/2? HTTP/2 is binary protocol if you are sending / receiving binary data, you ll get instant boost of throughput. (Base64) Resource-wise, HTTP/2 is more effecuve than its predecessor Persistent connecuons, streams*, compressed headers, Be aware of number of objects needed to process single HTTP request 45 E

46 HTTP/2 and JAX-RS Servlet 4.0: Status Update and HTTP/2 Comes to Java EE 8 [CON7980] Tuesday, Sep 20, 4:00 p.m. - 5:00 p.m. Parc 55 - Cyril Magnin II/III 46 E

47 HTTP/2 and JAX-RS HTTP/1.x HTTP/2 HTTP/2 + Push Ume How to use HTTP/2 features from JAX-RS? JAX-RS Servlet integrauon InjecUng HhpServletRequest, HhpServletResponse, ServletContext, ServletConfig 47 E

48 Java EE Roadmap Engage Java EE Community Feedback through Survey Launch Java EE Next JSRs Java EE 8 Specs, RI, TCK complete IniUal microservices support Define Java EE 9 Early access implementauon of Java EE 9 Java EE 9 Specs, RI, TCK complete Modular Java EE runume Enhanced microservices support 48 P

49 Next Steps Give us your feedback Take the survey hhp://glassfish.org/survey Send technical comments to (JAX-RS) (Java EE) Join the JCP come to Hackergarden in Java Hub hhps://jcp.org/en/parucipauon/membership_drive Join or track the JSRs as they progress hhps://java.net/projects/javaee-spec/pages/specificauons Adopt-a-JSR hhps://community.oracle.com/community/java/jcp/adopt-a-jsr 49 P

50 Where to Learn More at JavaOne Session Number Session Title Day / Time CON1558 What's New in the Java API for JSON Binding Monday 5:30 p.m. BOF7984 Java EE for the Cloud Monday 7:00 p.m. CON4022 CDI 2.0 Is Coming Tuesday 11:00 a.m. CON7983 JAX-RS 2.1 for Java EE 8 Tuesday 12:30 p.m. CON8292 Portable Cloud ApplicaUons with Java EE Tuesday 2:30 p.m. CON7980 Servlet 4.0: Status Update and HTTP/2 Tuesday 4:00 p.m. CON7978 Security for Java EE 8 and the Cloud Tuesday 5:30 p.m. CON7979 ConfiguraUon for Java EE 8 and the Cloud Wednesday 11:30 a.m. CON7977 Java EE Next HTTP/2 and REST Wednesday 1:00 p.m. CON6077 The Illusion of Statelessness Wednesday 4:30 p.m. CON 7981 JSF 2.3 Thursday 11:30 a.m. 50 P

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