<Insert Picture Here> Exploring Java EE 6 The Programming Model Explained

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1 <Insert Picture Here> Exploring Java EE 6 The Programming Model Explained Lee Chuk Munn chuk-munn.lee@oracle.com

2 The following is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, and timing of any features or functionality described for Oracle s products remains at the sole discretion of Oracle.

3 What's New in the Java EE 6 Platform? New and updated components EJB 3.1 (+Lite) JPA 2.0 Servlet 3.0 JSF 2.0 JAX-RS 1.1 Bean Validation 1.0 DI 1.0 CDI 1.0 Connectors 1.6 Managed Beans 1.0 Interceptors 1.1 JSP 2.2 EL 2.2 JSR JASPIC 1.1 JACC 1.5 JAX-WS 2.2 JSR

4 Changes in Java EE 6 23% 52% 11% 14% Unchanged Completely new Major updates Regular updates

5 Java EE 6 Web Profile CDI Extensio ns ns Web Cont ainer Extensions JSP JAX-RS 1.1 JSF JSTL 1.2 Servlet 3.0 / EL 2.2 DI 1.0 // CDI 1.0 // Interceptors 1.1 // JSR Managed Beans 1.0 EJB 3.1 JPA 2.0 // JTA 1.1 Bean Validation 1.0

6 Simplfied Packaging Java EE 5 Java EE 6 foo.ear foo_web.war WEB-INF/web.xml WEB-INF/classes com.sun.fooservlet com.sun.ticktock foo_ejb.jar com.sun.foobean com.sun.foohelper foo.war WEB-INF/classes com.sun.fooservlet com.sun.ticktock com.sun.foobean com.sun.foohelper

7 Web Apps Simplified Packaging Web Application WEB-INF/classes com/acme/myservlet.class com/acme/myfilter.class WEB-INF/lib someframework.jar WEB-INF/web.xml index.html main.css jquery js ui/jquery.ui.core.js ui/jquery.ui.widget.js

8 Web Apps Simplified Packaging Web Application WEB-INF/classes com/acme/myservlet.class com/acme/myfilter.class WEB-INF/lib /foo ) public class MyServlet { /foo ) public class MyFilter { } WEB-INF/web.xml index.html main.css jquery js ui/jquery.ui.core.js ui/jquery.ui.widget.js

9 Web Apps Simplified Packaging Web Application WEB-INF/classes com/acme/myservlet.class com/acme/myfilter.class WEB-INF/lib someframework.jar Framework Jar META-INF/web-fragment.xml com/fw/fwservlet.class com/fw/fwfilter.class index.html main.css jquery js ui/jquery.ui.core.js ui/jquery.ui.widget.js

10 Web Apps Simplified Packaging Web Application WEB-INF/classes com/acme/myservlet.class com/acme/myfilter.class WEB-INF/lib someframework.jar jquery-ui jar jquery Resource Jar META-INF/resources/jquery js META-INF/resources/ui/jquery.ui.core.js META-INF/resources/ui/jquery.ui.widget.js index.html main.css

11 Web Apps Simplified Packaging Web Application WEB-INF/classes com/acme/myservlet.class com/acme/myfilter.class WEB-INF/lib someframework.jar jquery-ui jar Simpler packaging Drag and drop self configuring frameworks Resource JARs index.html main.css

12 Managed Bean as the Foundation Plain Java objects (POJOs) Lifecycle managed by container Foundation for other component types Not something that developers would use directly Optional name Interceptors

13 Managed Bean MyCustomer ) public class Customer DataSource db; //Inject another managed Address address; private void init() { // }

14 EJB Components as Managed Beans All managed beans core services are available in EJB EJB component model extends managed beans by @Singleton EJBs can now be view as features on managed beans Just as other types of components

15 Incremental Programming Model Application changes over time Requirement change, functions of classes/objects changes Allows you to evolve your application gracefully Start with Use all the basic services lifecycle, resource injection, etc Turn them in to EJBs, Enitites, etc to take advantage of new capabilities No change to (local) client

16 Incremental Programming public class Customer DataSource db; //Inject another managed Address address; private void init() { // }

17 Incremental Programming public class Customer DataSource db; //Inject another managed Address address; private void init() { // }

18 Common Injection Service Framework Injection services available to all objects Not restricted to specific components eg. EJB Context and Dependency Injection Managed beans on steroids Opt-in technology on per-module basis WEB-INF/beans.xml, META-INF/beans.xml Key CDI concepts Strongly typed for typesafety Loose coupling events, interceptors, decorators Context and scope management Integration with EL Bridge EJB (business) to JSF (presentation)

19 CDI User user;

20 CDI User user; Type describes the capability of the user

21 CDI Example What type of User user;

22 User user; Qualifier describes the characteristic of the user

23 Uniformity Annotations are additive New behaviour refine pre-existing ones Unless annotation conflicts with the semantics of component Eg. session scoped for JAX-RS components Eg. JAX-RS resource classes are POJOs Use JAX-RS specific injection capabilities Additional annotations to turn resource classes into CDI managed beans or EJBs Use the new services with REST

24 JAX-RS root ) public class RootResource UriInfo {id} ) public SubResource id ) String id) { } } return (new SubResource(id));

25 JAX-RS Example As a managed @Path( root ) public class RootResource UriInfo DataSource {id} ) public SubResource id ) String id) { } } return (new SubResource(id));

26 JAX-RS Example As a CDI bean, and root ) public class RootResource DataSource {id} ) public SubResource id ) String id) { } } return (new SubResource(id));

27 APIs That Work Better Together Previous versions have a bunch of APIs that are quite independent of each other Java EE 5/6 introduces lots of 'services' API Managed bean, CDI, validation, interceptors, etc Aiming to get API to work better together Eg. Bean Validation integrated into JSF, JPA But not so well with CDI working on it Use of SPI to provide integration to other frameworks

28 Java EE 6

29 After Frameworks

30 Java EE 6 Platform Extensions

31 Extensibility Integrating 3 rd party frameworks Pluggability contracts make extension look like build-in technologies Two main extension points in Java EE 6 Servlet 3.0 pluggability CDI extensions

32 Servlet 3.0 Pluggability Primary to address 3 rd party web frames Drag and drop model Dynamic or static registration for frameworks Configuration, initialization, code generation, etc Results in ready to use framework JARs Modular web.xml and web-fragment.xml Framework contains a fragment of web.xml META-INF/web-fragment.xml Extension can discover and process annotated classes

33 Pluggability public class DoSomething { Register with service loader framework myframework.jar META-INF/services/ javax.servlet.servletcontainerinitializer myframework.frameworkloader

34 Pluggability public class FrameworkLoader implements ServletContainerInitializer { public void onstartup(set<class<?>> c, ServletContext ctx) { //Load framework controller ServletRegistration.Dynamic reg = ctx.addservlet( MyFrameworkController, myframework.controller.frameworkcontroller ); reg.setinitparameter( config, /WEB-INF/config.properties ); } } //Other processing eg. Code generation...

35 Extending CDI Portable extension framework provides standard way of extending CDI Drag and drop Extensions can process any annotated types What can you do with portable extensions Introduce new bean types Satisfy injection points Introduce custom scopes Augment or substitute bean's annotations and/or metadata Limited by your imagination

36 Portable public class HandleMessage { New JID EntityManager em; New bean type Integrates well {body} ) public Object handle(@named( body ) int custid) { return (em.find(customer.class, custid)); } Export a named bean to handle method only

37 Conclusion A Better Platform Less boilerplate code Simpler packaging Uniform use of annotations Consistent programming model Extensible Simple things should be simple complex things should be possible Alan Kay

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