Baking a Java EE 8 Micro Pi Mike Croft Ondrej Mihályi. Payara Support

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1 Baking a Java EE 8 Micro Pi Mike Croft Ondrej Mihályi Payara Support

2 Who are we? Payara Snowboarder Payara Proud father

3 What s this all about? How lightweight is Java EE, really? What s in Java EE 8 today? What could be in Java EE EE4J??? in the future?

4 A little (recent) history June 2013: Java EE 7 Released Docker was 3 months old WildFly was still JBoss AS (and no Swarm) Before Spring Boot WebSphere Liberty Profile recently released

5 A little (recent) history September 2017: Java EE 8 Released, 4 years later Docker is now the dominant container format WildFly have fully product-ised Swarm Spring Boot have been making JARs not WARs for a few years IBM released Open Liberty Payara entered the fray and released Payara Micro Eclipse MicroProfile is established and progressing

6 What s in Java EE 8? Upgrades JAX-RS 2.1 Servlet 4.0 Bean Validation 2.0 JSF 2.3 CDI 2.0 JSON-P 1.1 New Java EE Security JSON-B

7 What is Payara Micro? Payara Micro is Micro! (~60MB) Dynamically scalable Fully embeddable (if you want ) Web Profile plus On Maven Central <dependency> <groupid>fish.payara.api</groupid> <ArtifactId>payara-api</artifactId> <version>5.0.0-beta1-snapshot</version> <type>jar</type> </dependency>

8 What is Payara Micro? Key APIs Servlets, JSTL, EL, JSP WebSockets JSF JAX-RS EJB Lite JTA JPA JCA Bean Validation CDI Interceptors JBatch Concurrency JCache Config

9 Demo

10 Demo Scenario Stock! Micro Stock! Publish StockTicker events Listen on different endpoints

11 Demo Scenario Consumes Events StockWeb Websocket Push StockTicker Produces Events

12 Demo 1 Creating the Stock Ticker

13 Demo 2 Creating the Stock Web listener What do we need? Websocket endpoint Class to manage Websocket sessions Class to listen for Stock events on the CDI event bus Both these responsibilities can be in the same class

14 Integrating Java EE 8 Features

15 Demo Making our MicroService generic What do we need to change? Non-Payara services can t listen on the CDI event bus Solution: REST Server Sent Events (from JAX-RS 2.1) External services may not have access to a Stock object (or interface) Solution: Serialise our Stock object as JSON using JSON-B 1.0

16 Demo 3 JSON-P manual tojson() method private JsonObject tojson() { JsonObjectBuilder objectbuilder = Json.createObjectBuilder().add("symbol", symbol).add("description", description).add("price", price); return public String tostring() { return this.tojson().tostring();

17 Demo 3 JSON-B serialisation and public class Stock implements Serializable { private String private String private double price; Learn more: public String tostring() { JsonbConfig nillableconfig = new JsonbConfig().withNullValues(true); return JsonbBuilder.create(nillableConfig).toJson(this); private void observe() { source.register((sseevent) -> { this.stock = JsonbBuilder.create().fromJson(sseEvent.readData(), Stock.class); ); source.open();

18 Demo 4 JAX-RS reactive client API private void reactiveclient() { CompletionStage<Response> cs1 = ClientBuilder.newClient().target(" CompletionStage<Response> cs2 = ClientBuilder.newClient().target(" cs1.thencombine(cs2, (r1, r2) -> r1.readentity(string.class) + r2.readentity(string.class)).thenaccept(system.out::println); Source: Author: Alex Theedom

19 Demo 4 SSE server endpoint public EventOutput getjsonsse() { // We have to return the output, so we can't use try-with-resources. final EventOutput eventoutput = new EventOutput(); new Thread(new Runnable() public void run() { try { // Build and output a String representation of the Stock Object as an SSE. eventoutput.write(new OutboundEvent.Builder().name("stock-update").data(String.class, stockticker.getstock()).build()); catch (Exception ignored) { finally { try { eventoutput.close(); catch (IOException ioclose) { throw new RuntimeException("Error when closing the event output.", ioclose); ).start(); return eventoutput;

20 Demo 4 SSE server endpoint public void eventoutput(@context SseEventSink eventsink){ // send a single event eventsink.send(sse.newevent(stockticker.getstock().tostring())); // registers the requester as a consumer of @Consumes(MediaType.MULTIPART_FORM_DATA) public void broadcast(@formparam("event") String event){ // broadcasts the event to all registered consumers ssebroadcaster.broadcast(sse.newevent(event));

21 Demo 4 How do we orchestrate microservices? JAX-RS SSE Client StockWeb Javascript SSE Client StockTicker

22 Demo 4 SSE client consumer in Jersey private EventSource openeventsource() { //see Client client = ClientBuilder.newBuilder().register(SseFeature.class).build(); WebTarget target = client.target(stocktickerurl); EventSource eventsource = EventSource.target(target).build(); EventListener listener = new EventListener() public void onevent(inboundevent inboundevent) { ssestock = JsonbBuilder.create().fromJson(inboundEvent.readData(String.class), Stock.class); ; eventsource.register(listener, "stock-update"); eventsource.open(); return eventsource;

23 Demo 4 SSE client consumer in JAX-RS 2.1 private SseEventSource private void init() { Client client = ClientBuilder.newClient(); WebTarget target = client.target(stocktickerurl); source = SseEventSource.target(target).build(); observe(); private void observe() { source.register((sseevent) -> { this.stock = JsonbBuilder.create().fromJson(sseEvent.readData(), Stock.class);, Throwable::printStackTrace); private void destroy() { source.close();

Demo 4 SSE client consumer in Javascript @Provider public class CORSFilter implements ContainerResponseFilter { { @Override public void filter(final ContainerRequestContext requestcontext, final

24 Demo 4 SSE client consumer in public class CORSFilter implements ContainerResponseFilter { public void filter(final ContainerRequestContext requestcontext, final ContainerResponseContext cres) throws IOException // We need to add the right headers for the JS SSE client cres.getheaders().add("access-control-allow-origin", "*"); A resource makes a cross-origin HTTP request when it requests a resource from a different domain, protocol, or port to its own. Source:

25 The Future of Java EE?

26 Demo 5 Integrating MicroProfile 1.1 <dependency> <groupid>org.eclipse.microprofile</groupid> <artifactid>microprofile-bom</artifactid> <version>1.1.0</version> <type>pom</type> = "micro.pi.stockticker.url", defaultvalue = "NOT FOUND") private String stocktickerurl;

27 Demo 5 Integrating MicroProfile // Set system property java -jar -Dmicro.pi.stockticker.url= StockWeb/target/StockWeb-1.0-SNAPSHOT-microbundle.jar // Use asadmin to set property in Hazelcast cluster asadmin> set-config-property --propertyname=micro.pi.stockticker.url --propertyvalue= --source=cluster

28 Recap Java EE is incredibly adaptable to changing needs Recent change has been driven by vendors implementations Eclipse MicroProfile offers interesting ideas for the future

29 Questions?

MicroProfile - New and Noteworthy

MicroProfile - New and Noteworthy Ivar Grimstad Principal Consultant, Cybercom Sweden https://github.com/ivargrimstad https://www.linkedin.com/in/ivargrimstad Background MicroProfile Demo and Samples Monolithic