no-tier enterprise application mit cdi

No-Tier EnterpriseApplications with CDI

Lars Röwekamp | open knowledge

GmbH @mobileLarson

@_openknowledge

> Cool! JavaEE bietet IoC/DI > Cool! JavaEE bietet IoC/DI > Cool! JavaEE bietet IoC/DI > Cool! JavaEE bietet IoC/DI

> Aber was ändert > Aber was ändert sich?sich?

> SCHICHT 3

> SCHICHT 2

> SCHICHT 1TX Grenze

> UseCase: ausgewählten Kunden bearbeiten

Einmal den CustomerController, bitte ;-) Und für mich den

CustomerService, bitte!

Ok, dann brauch ich nen Customer mit der ID 147122, aber flott!

AA KK TT UU EE LL LL

AA UU SS GG EE WW ÄÄ HH LL TT EE

KK UU NN DD EE

RR

> Was wäre wenn ...? > Was wäre wenn ...? > Was wäre wenn ...? > Was wäre wenn ...?

LL II SS TT EE

MM EE II NN EE RR

EE II NN KK ÄÄ UU

> Oder wenn ...? > Oder wenn ...? > Oder wenn ...? > Oder wenn ...?

FF EE

> „No-Tier“

TX Grenze

J2EE 1.3 (JSR 58):

September 2001 Servlet 2.3 JSP 1.2 EJB 2.0

J2EE 1.4 (JSR 151):

November 2003 Servlet 2.4 JSP 2.0 EJB 2.1

01 / 02 03 / 04 05 / 06 07 / 08 09 / 10

Spring V1

Juni 2003

„Spring“

Oktober 2002

Java EE v5 (JSR 244):

Mai 2006 Servlet 2.5 JSP 2.1 / JSF 1.2 EJB 3.0

Java EE v6 (JSR 316):

Dezember 2009 Servlet 3.0 JSP 2.1 MR / JSF 2.0 EJB 3.1 JPA 2.0 CDI 1.0

Spring V3

Dezember 2009

Spring V2

Oktober 2006

CDI Konzepte > DI/IoC lite „Java EE without EJB“

> DI/IoC advanced LiceCyle Management und Scoping

> DI/IoC eXtreme Typensicherheit und lose Koppelung

> DI/IoC openExtension-Mechanismus

Teil 1: Base Features

Teil 1: Base Features

> @Inject> @Named> Sterotypes> Alternatives

Teil 1: Base Features

> Sope Singleton> Request> Conversation> Session> Application> Dependant*> Singleton*> Cleanup*Pseudo-Scope

Teil 1: Base Features

Teil 1: Base Features

> Events> Observer> Interceptors

Teil 1: Base Features

> Qualifier> Stereotypes> Alternatives

> Was haben wir > Was haben wir gewonnen?gewonnen?> Was haben wir > Was haben wir gewonnen?gewonnen?

> SCHICHT 3

> SCHICHT 2

> SCHICHT 1

> SCHICHT 3

> SCHICHT 2

> SCHICHT 1

import javax.inject.Named;import javax.inject.Inject;import javax.enterprise.context.RequestScoped;

@Named(“hello“)@RequestScopedpublic class HelloBean {

@Inject Greeter greeter;

private String name;

public String getGreeting() {return greeter.greet(name);

}

// getter and setter for name attribute...}

CDI Managed Bean

„hello“ für EL„hello“ für EL

gültig für Requestgültig für Request

Injection PointInjection Point

Cool, aber geht da

nicht mehr?

CDI Mehrwert

FACHLICHE Injektion statt „nur“

Infrastruture Injection

eCustomer - Beispiel

CDI Refactoring

> CDI Wiring

> CDI Current User

> CDI Beans only

> CDI Style Views

> CDI Events

CDI Refactoring

> CDI Wiring

> CDI Current User

> CDI Beans only

> CDI Style Views

> CDI Events

CDI Refactoring

> CDI Wiring

> CDI Current User

> CDI Beans only

> CDI Style Views

> CDI Events

eCustomer - CDI Current User

> Producer Methods & Fields

> „Factory Method“ Pattern für Objekte

> @Produces als Mittel zum Zweck

> @Qualifier als Mittel zur Qualifizierung

> Ermöglicht nicht nur Infrastruktur

sondern vor allem auch fachliche

Injection.

eCustomer - CDI Current User

package de.openknowledge.qualifier;

import ...

@Qualifier@Target({TYPE, METHOD, PARAMETER, FIELD})@Retention(RUNTIME)public @interface Current{}

Self-made QualifierSelf-made Qualifier

eCustomer - CDI Current User

@Named@SessionScopedpublic class AuthenticationController implements Serializable {

private User authenticatedUser; public String authenticate() {...}

@Produces @Current public User getAuthenticatedUser() {...}

...}

AuthenticationControllerAuthenticationController

@Inject @Current User user; @Inject @Current User user;

Use Case „Kunde bearbeiten“

@Statelesspublic class CustomerServiceEJB

implements CustomerService {

@Inject @Current private User currentUser;

@PersistenceContext private EntityManager em;

// updates the customer - needs a transaction public Customer updateCustomer(Customer customer) { customer.updateAuditInformation(currentUser); return em.merge(customer); }}

CustomerService EJBCustomerService EJB

CDI Refactoring

> CDI Wiring

> CDI Current User

> CDI Beans only

> CDI Style Views

> CDI Events

eCustomer - CDI Beans only

> Injizierbare CDI Ressourcen

> „normale“ Java Klassen, optional mit

@Named oder @Qualifier markiert

> EJBs, wie Stateless, Stateful, Singleton

> Sonstige Java EE Ressourcen, wie

PersistenceContext, UserTransaction

eCustomer - CDI Beans only

@Stateless// no annotation required!public class CustomerServiceBeanEJB

implements CustomerService {

@PersistenceContext private EntityManager em;

// updates the customer - needs a transaction public Customer updateCustomer(Customer customer) { return em.merge(customer); }

...

}

CustomerService CDICustomerService CDI

eCustomer - CDI Beans only

@Stateless// no annotation required!public class CustomerServiceBeanEJB

implements CustomerService {

@PersistenceContext private EntityManager em;

// updates the customer - needs a transaction public Customer updateCustomer(Customer customer) { return em.merge(customer); }

...

}

CustomerService CDICustomerService CDI

Und Transaktionen?!Und Transaktionen?!

Bauen wir uns selbst ...Bauen wir uns selbst ...

eCustomer - CDI Beans only

// simple pojo // no annotation required!public class CustomerServiceBean

implements CustomerService {

@PersistenceContext private EntityManager em;

@Transactional public Customer updateCustomer(Customer customer) { return em.merge(customer); }

...

}

CustomerService CDICustomerService CDI

CDI Interceptor

s

eCustomer - CDI Beans only

@InterceptorBinding@Retention(RetentionPolicy.RUNTIME)@Target({ElementType.METHOD, ElementType.TYPE})

public @interface Transactional { public TransactionalType value()

default TransactionalType.REQUIRED; }

Transactional AnnotationTransactional Annotation

??

eCustomer - CDI Beans only

@Transactional @Interceptorpublic class TransactionInterceptor {

@Inject private UserTransaction utx;

@AroundInvoke public Object applyTransaction( InvocationContext ic) throws Throwable {

... // implement utx.begin() ic.proceed(); // call original method ... // implement utx.commit()

} }

*XML registration omitted

Transactional Interceptor*Transactional Interceptor*

eCustomer - CDI Beans only

// no annotation required!public class CustomerServiceBean

implements CustomerService {

@PersistenceContext private EntityManager em; @de.openknowledge.qualifier.Transactional public Customer updateCustomer(Customer customer) { return em.merge(customer); }

...

}

CustomerService CDICustomerService CDI

inkl. Transaktioninkl. Transaktion

> SCHICHT 3

> SCHICHT 2

> SCHICHT 1TX Grenze

> SCHICHT 3

> SCHICHT 2

> SCHICHT 1

TX Grenze

eCustomer - CDI Beans only

@Named@SessionScopedpublic class CustomerBean implements Serializable {

@Inject private CustomerService customerService;

@de.openknowledge.qualifier.Transactional public String update() { customerService.updateCustomer(currentCustomer); return Outcome.SUCCESS; } ...}

CustomerBean CDICustomerBean CDI

inkl. „fachliche“ Transaktioninkl. „fachliche“ Transaktion

CDI Refactoring

> CDI Wiring

> CDI Current User

> CDI Beans only

> CDI Style Views

> CDI Events

eCustomer - CDI Style Views

> CDI Conversations

> @ConversationScoped

> conversation.begin() / .end()

> CDI „Backing Beans“

> @Produces in Kombination mit @Named

> „self-made“ Qualifier

eCustomer - CDI Style Formulare

@javax.inject.Named@javax.context.enterpise.ConversationScopedpublic class CustomerBean implements Serializable {

private Customer customer;

@javax.inject.Inject private Conversation conversation;

public String selectCustomer(Customer customer) { this.customer = customer; conversation.begin(); ... } ... }

CustomerBean (1/2)CustomerBean (1/2)

eCustomer - CDI Style Formulare

@javax.inject.Named@javax.context.enterpise.ConversationScopedpublic class CustomerBean implements Serializable {

...

public String update() { conversation.end(); ... } ...

}

CustomerBean (2/2)CustomerBean (2/2)

endet mit aktuellen Requestendet mit aktuellen Request

eCustomer - CDI Style Formulare

<html ...> <h:body> <h:form>

Vorname: <h:inputText value=“#{customerBean.customer.firstname}"/> Name: <h:inputText value=“#{customerBean.customer.lastname}"/>

</h:form> </h:body></html>

Infrastructure in der View!Infrastructure in der View!

eCustomer - CDI Style Formulare

@javax.inject.Named@javax.context.enterpise.ConversationScopedpublic class CustomerBean implements Serializable {

private Customer customer;

@javax.inject.Produces @javax.inject.Named(“selectedCustomer“) @de.openknowledge.qualifier.Selected public Customer getSelected { return customer; } ... }

CustomerBean CustomerBean

eCustomer - CDI Style Formulare

<html ...> <h:body> <h:form>

Vorname: <h:inputText value=“#{selectedCustomer.firstname}"/> Name: <h:inputText value=“#{selectedCustomer.lastname}"/>

</h:form> </h:body></html>

Fachlichkeit in der View!Fachlichkeit in der View!

CDI Refactoring

> CDI Wiring

> CDI Current User

> CDI Beans only

> CDI Style Views

> CDI Events

eCustomer - CDI Events

> Java EE Observer Pattern, inkl. ...

> Event Object & Event Producer

> Observer Method

> „besondere“ Eigenschaften

> schichtenneutral auch für POJOs

> (ggf.) transaktionsgebunden

> synchrone Interaktion

eCustomer - CDI Events

„User created!“„User created!“

„Und ich auch!“„Und ich auch!“„Ah, interessant.“„Ah, interessant.“

„Finde ich!“„Finde ich!“

eCustomer - CDI Events

> Ok, aber ...

> Wie sieht ein solches Event aus?

> Und wie fange ich es?

> Und vor allem: wie löse ich es aus?

eCustomer - CDI Events

public class CustomerCreatedEvent {

private Customer customer;

public CustomerCreatedEvent(Customer customer) { this.customer = customer; }

public Customer getCustomer() { ... }}

Customer Created Event (1/3)Customer Created Event (1/3)

„Wie sieht ein solches Event aus?“

eCustomer - CDI Events

public void sendWelcomeMail( @Observes CustomerCreatedEvent event) { Customer customer = event.getCustomer(); ...}

Customer Created Event (2/3)Customer Created Event (2/3)

„Und wie fange ich es?“

eCustomer - CDI Events

@Injectprivate Event<CustomerCreatedEvent> eventSource;

public String createCustomer() {

Customer customer = ...; eventSource.fire( new CustomerCreatedEvent(customer) ); ... }

Customer Created Event (3/3)Customer Created Event (3/3)

„Und vor allem: Wie löse ich es aus?“

eCustomer - CDI Events

public void sendWelcomeMail( @Observes CustomerCreatedEvent event @Created Customer customer) { Customer customer = event.getCustomer(); ...}

Qualified CDI Event (2/3)Qualified CDI Event (2/3)

„Und wie fange ich es?“

eCustomer - CDI Events

@Inject @Created private Event<Customer> eventSource;

public String createCustomer() { Customer customer = ...; eventSource.fire(customer); ... }

Qualified CDI Event (3/3)Qualified CDI Event (3/3)

„Und vor allem: Wie löse ich es aus?“

eCustomer - CDI Events

„Wow! Observer mit Qulifiern - das muss ich erst einmal sacken lassen!“

„Und das ist erst die Spitze des Eisberges - schau dir

mal die CONDITIONAL OBSERVER METHODS hier

an!“

eCustomer - CDI Events

// Conditional Observer Method that takes // - Transaction status, e.g. AFTER_SUCCESS, // AFTER_FAILURE// - Bean instance status, e.g. ALLWAYS// into accountpublic void sendWelcomeMail( @Observes( receive=ALLWAYS, // bean during=AFTER_SUCCESS // tx ) @Created Customer customer) { ... }

Conditional Observer MethodsConditional Observer Methods

> „No-Tier“

TX Grenze

XFazit:

CDI Fazit

CDI ermöglicht ...

“Java Enterprise Development without EJB - and without Spring“

CDI bietet dafür ...

„typesafe und schichtenneutrales Injection Framework für fachliche und technische Injection sowie ein Rahmenwerk für eventgetriebene Entwicklung.“

Gibt es noch Fragen?

Dann los ...

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