OpenWebBeans/Web Beans

Apache Incubator OpenWebBeans Gurkan Erdogdu Conny Lundgren Matthias Wessendorf Kevan Miller Apache Incubator Free and Open Source

What is OpenWebBeans Implementation of the JSR-299 WebBeans Incubated in the Apache Software Foundation http://incubator.apache.org/openwebbeans http://incubator.apache.org

What is a WebBeans? Dependency injection service between Java EE components EJB Components Servlet Components Java Beans Components Easy use of EJB 3.1 components as first class managed bean in the JSF environment Type-safe API deployment Interceptors and Decorators

Continue... Loosely coupled components with powerful Event and Observer mechanism Context management Conversation context ? Lifecycle management Manages all of the Java EE components lifecycles Extensible Easily extensible with Manager runtime

Web Bean Definition Simple Web Beans No action is required Every Java Beans is a simpe web bean Enterprise Web Beans EJB session beans Producer Methods JMS Endpoints

Web Bean Definition API Types Binding types Scopes Deployment types Names StereoTypes Specialization

API Type Simple Web Bean public class Bean implements IBean{} Class, super class and interfaces, directly or indirectly Above : Bean, IBean, Object EJB Components @Stateless class PaymentProcessorImpl implements PaymentProcessor { ... } LocalInterfaces Above : Local interfaces (PaymentProcessor)

API Type continue Producer Methods public Product getProduct(){} Return type, super class, interfaces directly or indirectly Above : Product, Object JMS End points Queue : Queue, QueueConnection, QueueSession and QueueSender + Object Topic : Topic, TopicConnection, TopicSession and TopicPublisher + Object

Binding Types Seperates implementations from each other Annotation driven Annotated with @BindingType Example, 2 binding types @BindingType public @interface CreditCardPayment @BindingType public @interface DebitCardPayment

Binding Types One interface, two implementation, dependency injection, just BindingType ? Seperation with @BindingType, HOW? public class PaymentProcessor{ Ipayment payment; -> Which payment type? } public class PaymentProcessor{ @CreditCardPayment IPayment payment; -> Credit Card } public class PaymentProcessor{ @DebitCardPayment IPayment payment; -> Debit Card }

Scopes RequestScoped SessionScoped ApplicationScoped ConversationScoped DependentScoped Or your defined scope, annotated @ScopeType @ScopeType Public @interface MyScope{}

Deployment Types Cleanly seperate your beans at run time Test environment enabled Web Beans or Production ready web beans Easy test your beans Example: @Production -> Use in my production run time public class PaymentProcessor implement Processor { } @Test -> Use in my test run time public class TestProcessor implement Processor { } Injection : Processor instance ??? -> which bean it selects?

Name Web Beans has name @Named annotation @Named(value=”actual name”) Default Name, if no value is provided Class Name -> public class PaymentProcessor Name : paymentProcessor Method name -> Products getProducts() Name : products No name is no @Named annotation

StereoTypes Like class inheritance No repeat yourself Just inherit model Inherit annotations Annotated with @StereoType @StereoType @RequestScoped @Production @Named public @interface MyStereoType

StereoType Easily create web bean annotations EXAMPLE : MyNewBean inherits from stereotypes. @MyStereoType public class MyNewBean{} Inherit :ScopeType, DeploymentType and Default Named indicator from MyStereoType

Specialization Related with web beans resolution semantic Clear in the next slides Normally injection service resolves web beans with API type Binding Type Precedence

Specialization Lets say two DeploymentType Type1 and Type2 and Type1 precedence > Type2 Normally we want Production @BindingType1 @Type1 Public class Production{} @BindingType2 @BindingType1 @Type2 Public class Mock{}

Specialization public class PaymentProcessor { @BindingType2 @BindingType1 IPayment payment; -> we want Production?? } But gets Mock??? Why? Resolution rules? If we want always selectinh Production type web beans without Binding Type, then @Specializes rescue @Specializes public class Production extends Mock{} -> Inhertis all BindingTypes of Mock., now, @BindingType2 Ipayment payment selects Production

Resolutions Resolution By Name Name Precedence of the DeploymentType Resolution By Type API Type BindingType Precedence of the DeploymentType

Injected Fields Inject fields of the web beans Public class MyBean { @Logger Log logger; -> Inject for me after creation }

Initializer Methods Initializer Methods of the web bean @Production Public class PaymentProcessor { Ipayment payment; @Initialize public void createPaymentProcessor(@CreditCard IPayment processor) -> Inject for me after creation this.payment = processor; }

Constructor Initializer Inject into web beans constructor @Production @RequestScoped public class PaymentProcessor { -> Inject into the my constructor while creating public PaymentProcessor(@CreditCard Ipayment payment) { } }

EL Resolution EL Resolution Resolve by name Use in JSF or JSP page @RequestScoped @Named public class LoginBean @Produces @SessionScoped @LoggedInUser @Named(value="currentUser") public User getLoggedInUser() { return this.user ; } public void login() { User user = new User(); this.user = user;}

EL Resolution <h:inputText id="userName" value="#{loginBean.userName}"></h:inputText> <h:inputText id="password" value="#{loginBean.password}"></h:inputText> <h:commandButton action="#{loginBean.login}" value="Login"></h:commandButton>

EL Resolution Welcome Page, gets user name and password from the @CurrentUser <div align="right"> <h:commandLink value="Logout" action="#{logoutBean.logout}"></h:commandLink> </div> <div> <h:outputText value="Merhaba #{currentUser.userName} #{currentUser.password}"></h:outputText> </div>

LifeCycle of WebBeans Create Inject fields Initialize Methods Life cycle annotations, @PostConstruct, @PreDestroy Interceptors for orthogonal processes Decorators for business processes Common annotations, @EJB Destroy

Interceptors Interceptor with @InterceptorBindingType @InterceptorBindingType Public @interface Transactional{} -> Interceptor @Transactional -> Class level Public class Payment{ @Transactional -> Method level public void payment(){} }

Interceptors Business Level Interceptors Business method invocation Life Cycle Interceptors Web Bean life cycle @PostConstruct @PreDestroy @PrePassivate @PreActivate

Interceptor Example @Transactional public class MyTransactionInterceptor { @AroundInvoke -> called just before my business method public void invoke(InvocationContext context) { } }

Decorators For specific business method Can be abstract Example: @Decorator public class MyDecorator implement Ipayment { @Decorates @CreditCard IPayment payment; -> Specific web bean public void pay() -> Specific business method { } }

Events Loosely Coupled Interaction Events Event type Event binding type Observers Observable annotation Transactional observers

Observers public class PaymentObserver implements Observer<PaymentDoneEvent> { public void notify(PaymentDoneEvent event) { } }

Events @Observes annotation, observes given event type public class PaymentDoneBean { public void afterPayment(@Observes PaymentDoneEvent event) { } }

Events Fire events via Manager API public void pay() { manager.fireEvent(new PaymentDoneEvent(user)) }

Event @Observable annotation Register observers via event Custom web bean with Event API Fire events via event public class LoginBean { private @Observable Event<LoggedInEvent> event; -> Runtime provided Event bean public void afterLoggedIn() { LoggedInEvent loggedIn = new LoggedInEvent("Gurkan"); event.fire(loggedIn, anns); -> Fire event via Event }

Scope and Contexts Active Scope Active context with respect to the current thread Passive Scope Passive context with respect to the current thread ContextNotActiveException if access Context passivation Passivation in passivated type context. Save its context info into the disk

XML Configuration Some third party class Not able to annotate Candidate for XML configuration XML namespace for Java package <WebBeans xmlns="urn:java:javax.webbeans" xmlns:myapp="urn:java:com.mydomain.myapp"> ... </WebBeans>

Java EE 6.0 JSR- 316 Easy management of the Enterprise Projects

Questions QUESTIONS?? Thank you!

OpenWebBeans/Web Beans

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