Java EE6 CDI

The New Java EE CDI -‐ the re-‐invented component model for Java EE 6. BeAer than Spring? Johan Eltes | johan.eltes@callistaenterprise.se | Cadec 2010-‐01-‐20 onsdag 27 januari 2010 1

Spring wasn’t built bottom up for noxml Spring wasn’t built bo?om up for noXML You need to understand what can be done using JavaConﬁg / annotaFons and when to step down to XML. There are so many options in Spring that you need a 100 page company-best-practice guide so that developers can read each others code. 4 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 4

Meanwhile, Java EE is shrinking... o Rile Pr eb 6 W a EE Jav E va E l l Ja Fu 6 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 6

...and moving to a very slick DI-based component model: CDI CDI requires support from an EJB 3.1 Light-‐ container for EJB-‐ CDI container (injecKon, aop, contexts) specific capabiliKes (transatcions, security) JSF/Facelets Managed Bean Special case: EJB Session and Singleton CDI container CDI container will offer the will resolve bean for dependency injecKon Servlets MDBs WS CDI consolidates JSR 250 (common annota7ons), JSR-‐330 ( javax.inject) and “EJB 3.1 light” into a unified “POJO” component model. 7 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 7

So, let’s have a look at CDI! All demo code for the use-cases are available for public checkout at this svn repo: • Use-‐cases for CDI https://svn.callistaenterprise.se/public/Cadec/Cadec2010/cdi/trunk – UC 1: Basic DI for Unit tesKng – UC 2: Factories and qualiﬁers – UC 3: IntegraKon tesKng in JUnit – UC 4: AOP with interceptors – UC 5: Loose coupling with events – UC 6: Handling of scopes – UC 7: Extensions AnnotaKons, annotaKons, annotaKons... @Inject, @Produces, @Qualifer, @AlternaKve, @Stateless, @ConversaKon 8 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 8

UC 1: Basic DI for Unit testing Interface: OrderDao Class OracleOrderDaoImpl extends Class OrderServiceImpl { OrderDao @Inject OrderDao orderDao; ... ? } Class MySqlOrderDaoImpl extends OrderDao Class MockOrderDaoImpl extends OrderDao @Inject is by default auto-‐injecKon by type 9 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 9

9 UC 2: Factories and qualiRiers Instance of Class JmsTemplate: @DestClass(ERROR) Interface: receiveTimeout: 3000 defaultDestinationName: “error.queue” JmsTemplate ... Instance of Class JmsTemplate: @ DestClass(LOG) Class OrderServiceImpl { receiveTimeout: 100 @Inject defaultDestinationName: “log.queue” JmsTemplate @JTQualifer(ERROR) ... errorDestTemplate; ? ... Instance of } Class JmsTemplate: @Named(“service1”) receiveTimeout: 4000 defaultDestinationName: “service1” ... Class JmsTemplateFactory { @Producer @DestClass(ERROR) JmsTemplate getErrorDestTemplate() {} @Producer @DestClass(LOG) JmsTemplate getLogDestTemplate() {} @Producer @Named(“invoice”) JmsTemplate getInvoiceDestTemplate() {} } With @Produces we can create mulKple beans of the same type With @Qualiﬁer-‐annotaKons, we select which bean to inject 10 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 10

UC 3: Integration testing with JUnit How much weight has EJB lost?? Demo: JUnit TestCase-‐>TestEjb-‐>Ejb-‐>Dao-‐>JPA ...with embeddable EJB container 11 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 11

9 UC 4: Cross-cutting concerns Class OrderServiceImpl { Interface: OrderDao @Inject @Trace OrderDao orderDao; Class OracleOrderDaoImpl extends OrderDao ... { } Order save(Order order) { } } @Trace @Interceptor public class TraceLogInterceptor { @AroundInvoke public Object trace(InvocationContext ctx) throws Exception { ... } } Sample: Trace entry and exit of method invocaKons in all classes annotated with @Trace 12 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 12

UC 5: Events Class CustomerFormBean { @Inject Class CustomerServiceImpl { CustomerService cs; @Inject @Deleted Event<Customer> public void delete(Customer deletedEvent; c) { cs.delete(c) public void delete(Customer c) } { } ... “CDI Event broker” deletedEvent.fire(c); } Class OrderServiceImpl { } @Inject OrderDao od; public void validateDelete(@Observes @Deleted Customer c) { if (od.hasOrderForCustomer(c)) throw new VetoExcepKon(); } } Order service listens to customer deleKon events to prevent deleKon of customers with orders. 13 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 13

UC 6: Declarative scope management • ejb Session CDI handles the scoping / context aspects of EJBs as • ejb Singleton well (without an EJB container) • ApplicaKonScoped • RequestScoped • SessionScoped • ConversaKonScoped • AddiKonal scopes may be added via extenKon api (“SPI”) Use-‐case 5: Contextual services 14 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 14

9 UC 7: Extentions - Sample: conRig Rile Instance of Class JmsTemplate: @DestClass(ERROR) Interface: receiveTimeout: 3000 defaultDestinationName: “error.queue” JmsTemplate ... Instance of Class JmsTemplate: @ DestClass(LOG) Class OrderServiceImpl { receiveTimeout: 100 @Inject defaultDestinationName: “log.queue” JmsTemplate @JTQualifer(ERROR) ... errorDestTemplate; ? ... Instance of } Class JmsTemplate: @Named(“invoice”) receiveTimeout: 4000 defaultDestinationName: “invoice.queue” ... Class JmsTemplateFactory { @Producer @DestClass(ERROR) JmsTemplate getErrorDestTemplate() {} @Producer @DestClass(LOG) JmsTemplate getLogDestTemplate() {} @Producer @Named(“invoice”) JmsTemplate getInvoiceDestTemplate() {} } Sample: Extension for ﬁle-‐based conﬁguraKon of @Producers 15 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 15

Is Java EE 6 and CDI for me? • Why? – Java EE development is FUN (producKve) again! – It is a neat, simple model – Zero config / overhead / layers if you want to start simple – Do we sKll need “help” from Spring? • When? – JBoss, Oracle and Sun seems to be there “soon” – Likely to get OS-‐extensions that bring it to Tomcat very soon • Who? – Very good news for no-‐floss-‐shops :) – OpKon for building up Spring competence -‐ Java EE 6 Web Profile is likely an easier start 16 CDI -‐ the re-‐invented component model for Java EE 6 © 2010 Callista Enterprise | www.callistaenterprise.se onsdag 27 januari 2010 16

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Java EE6 CDI

by Johan Eltes on Jan 24, 2010

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Java EE6 CDI — Presentation Transcript