What's New in CDI 2.0 at JUG HH

Slides to the talk I gave at JUG Hamburg.

Code: https://github.com/mp911de/cdi-2.0

Transcript

1. What's New in CDI 2.0 JSR 365 Mark Paluch • @mp911de
2. Mark Paluch @mp911de ‣Software Craftsman ‣Spring Data Engineer @ Pivotal ‣EG for CDI 2.0 (JSR365)
3. CDI Timeline Dec 2009 CDI 1.0 (Java EE 6) Jun 2013 CDI 1.1 (Java EE 7) Apr 2014 CDI 1.2 (M R) Sep 2014 CDI 2.0 (Kickoff) May 2017 CDI 2.0 (Release) Jul 2018 CDI 2.0 SP1 (Bugfix)
4. CanDI
5. Road towards JavaEE 8 • Java 8 baseline • Spec split: Core/SE/EE CDI Specification CDI Core CDI for Java SE CDI for Java EE
6. JavaEE 8 Implementations • IBM OpenLiberty 18 • GlassFish 5 • WildFly 14
8. Events
9. @Observes
10. @ObservesAsync
11. Asynchronous Events • Notify event observers asynchronously • One or more different threads • Decoupled from synchronous events
12. Firing Async Events @Inject
 private Event<MyEventPayload> event;
 public void triggerEvent() {
 event.fireAsync(new MyEventPayload());
 }
13. Firing Async Events @Inject
 private Event<MyEventPayload> event;
 public void triggerEvent() {
 event.fireAsync(new MyEventPayload());
 }
14. Observing Async Events public void observer(@ObservesAsync MyEvent payload) {
 System.out.println("Yay, I'm called async!");
 }
15. How it works @Observes @ObservesAsync event.fire(…) Sync call Not notified event.fireAsync(…) Not notified Async call
16. Asynchronous Events • Exceptions and Synchronization with CompletionStage • Active scopes: Request, Application • Custom scopes depend on the implementation
17. @Priority
18. Ordered Events • Add @Priority to event observers • Aids observer ordering • Total global order determined when the event is fired
19. Observer Ordering public void observer(@Observes @Priority(2500) MyEvent event) {
 System.out.println("Default priority");
 }
20. public void earlier(@Observes @Priority(2499) MyEvent event) {
 // yay! I'm first
 System.out.println("Notified before all other observers");
 }
 public void observer(@Observes MyEvent event) {
 System.out.println("Default priority");
 } public void later(@Observes @Priority(2501) MyEvent event) {
 System.out.println("Notified after all other observers");
 }
21. public void earlier(@Observes @Priority(2499) MyEvent event) {
 // yay! I'm first
 System.out.println("Notified before all other observers");
 }
 public void observer(@Observes MyEvent event) {
 System.out.println("Default priority");
 } public void later(@Observes @Priority(2501) MyEvent event) {
 System.out.println("Notified after all other observers");
 }
22. public void earlier(@Observes @Priority(2499) MyEvent event) {
 // yay! I'm first
 System.out.println("Notified before all other observers");
 }
 public void observer(@Observes MyEvent event) {
 System.out.println("Default priority");
 } public void later(@Observes @Priority(2501) MyEvent event) {
 System.out.println("Notified after all other observers");
 }
23. public void earlier(@Observes @Priority(2499) MyEvent event) {
 // yay! I'm first
 System.out.println("Notified before all other observers");
 }
 public void observer(@Observes MyEvent event) {
 System.out.println("Default priority");
 } public void later(@Observes @Priority(2501) MyEvent event) {
 System.out.println("Notified after all other observers");
 }
24. Java SE
25. Java SE • Currently: Implementation-specific in Weld/ OpenWebBean • Spec Goal: Bootstrap API
26. SeContainerInitializer initializer = SeContainerInitializer .newInstance()
 .disableDiscovery()
 .addBeanClasses(MyApp.class)
 .addPackages(MyOtherServices.class)
 .addExtensions(MyExtension.class);
 
 try (SeContainer container = initializer.initialize()) {
 
 MyApp service = container.select(MyService.class).get();
 service.runMyApplication();
 }
27. SeContainerInitializer initializer = SeContainerInitializer .newInstance()
 .disableDiscovery()
 .addBeanClasses(MyApp.class)
 .addPackages(MyOtherServices.class)
 .addExtensions(MyExtension.class);
 
 try (SeContainer container = initializer.initialize()) {
 
 MyApp service = container.select(MyService.class).get();
 service.runMyApplication();
 }
28. SeContainerInitializer initializer = SeContainerInitializer .newInstance()
 .disableDiscovery()
 .addBeanClasses(MyApp.class)
 .addPackages(MyOtherServices.class)
 .addExtensions(MyExtension.class);
 
 try (SeContainer container = initializer.initialize()) {
 
 MyApp service = container.select(MyService.class).get();
 service.runMyApplication();
 }
29. Portable Extensions
30. SPI
31. CDI Extensions • http://www.cdi-spec.org/ ecosystem/
32. Meta-Data Builder API • Standardized API • CDI 1.0+: Very verbose to create • AnnotatedTypes, Beans, BeanAttributes, InjectionPoints, and ObserverMethods • Builder and Configurator-style
33. public class MyExtension {
 public void afterBeanDiscovery( @Observes AfterBeanDiscovery event) {
 event.addBean() .beanClass(MyService.class) .scope(RequestScoped.class) .name("myservice"); } } Add a Bean
34. public class MyExtension {
 public void afterBeanDiscovery( @Observes AfterBeanDiscovery event) {
 event.addBean() .beanClass(MyService.class) .scope(RequestScoped.class) .name("myservice"); } } Add a Bean
35. public class MyExtension {
 public <T> void processAnnotatedType(@Observes @WithAnnotations(UseCase.class) ProcessAnnotatedType<T> pat) {
 
 pat.configureAnnotatedType() .methods() 
 .forEach(m -> m.add(CacheableLiteral.INSTANCE));
 } } Add annotation to Methods
36. public class MyExtension {
 public <T> void processAnnotatedType(@Observes @WithAnnotations(UseCase.class) ProcessAnnotatedType<T> pat) {
 
 pat.configureAnnotatedType() .methods() 
 .forEach(m -> m.add(CacheableLiteral.INSTANCE));
 } } Add annotation to Methods
37. AOP on produced Bean • CDI 1.0+: Interceptor applied to producer method • InterceptionFactory a possible answer @Produces 
 @Transactional
 public MyService produceService() {
 ... 
 }
38. AOP on produced Bean @Produces
 @RequestScoped
 public MyService createTransactional(InterceptionFactory<MyService> ipf) {
 
 ipf.configure()
 .filterMethods(m -> m.getJavaMember().getName().equals("save"))
 .findFirst()
 .ifPresent(m -> m.add(new AnnotationLiteral<Transactional>() {}));
 
 return ipf.createInterceptedInstance(new MyService());
 }
39. AOP on produced Bean @Produces
 @RequestScoped
 public MyService createTransactional(InterceptionFactory<MyService> ipf) {
 
 ipf.configure()
 .filterMethods(m -> m.getJavaMember().getName().equals("save"))
 .findFirst()
 .ifPresent(m -> m.add(new AnnotationLiteral<Transactional>() {}));
 
 return ipf.createInterceptedInstance(new MyService());
 }
40. Proxy matters
41. Proxy injection @Inject
 private MyService myService; This is a proxy instance
42. Proxy injection
43. Proxy injection
44. Proxy injection @Inject @Named("myBean")
 private ConcurrentHashMap<String, String> myService; /** Implementation for put and putIfAbsent */
 final V putVal(K key, V value, boolean onlyIfAbsent)
45. Normal-scoped beans • Must be proxyable • accessible, no-args constructor • non-final classes • accessible, non-final instance methods
46. Enabling proxying @Produces
 @RequestScoped
 public MyService createTransactional(InterceptionFactory<MyService> factory) {
 
 factory.ignoreFinalMethods(); 
 return factory.createInterceptedInstance(new MyService());
 }
47. Enabling proxying @Produces
 @RequestScoped
 public MyService createTransactional(InterceptionFactory<MyService> factory) {
 
 factory.ignoreFinalMethods(); 
 return factory.createInterceptedInstance(new MyService());
 }
48. Get in touch Web: cdi-spec.org Mailing list: cdi-dev@lists.jboss.org IRC: irc://freenode.net/#cdi-dev Twitter: @cdispec // @mp911de Github: github.com/cdi-spec CDI 2.0 JCP page: jcp.org/en/jsr/summary?id=365