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

EL Resolution

Welcome Page, gets user name and password from the @CurrentUser

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

{

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 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

...

Java EE 6.0

JSR- 316

Easy management of the Enterprise Projects

Questions

QUESTIONS??

Thank you!

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