Java EE Development without EJB - and without Spring - Part 2

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In den nächsten 60 Minuten

Refactoring !the Java EE CDI way!

eCustomer Beispiel

§  Java EE Anwendung zur Online-Verwaltung von Kunden

§  View: Login Screen, Übersicht der Kunden, Kunde anlegen, Kunde bearbeiten, Kunde löschen

§  Model: User (Admin), Kunde

Demo time...!

§  Architekturansatz § Mehrschicht-

architektur

§  Bausteine §  JSF xhtml Seiten

§  Formularobjekte

§  Services

§  Persistente Domain Objekte (User,...)

eCustomer Beispiel

§  *.xhtml §  AuthenticationBean

§  CustomerBean

§  CustomerService(EJB)

§  Customer

Use Case Kunde bearbeiten

§  JSF AuthenticationBean

@ManagedBean!@SessionScoped!public class AuthenticationBean! implements Serializable {!! private User authenticatedUser;! ! public String authenticate() {...}!! public User getAuthenticatedUser() {...}!}!!

§  View customer/edit.xhtml

<html ...><h:body>! <h:form>!! Vorname: <h:inputText ! value=“#{customerBean.firstname}"/>! Name: <h:inputText ! value=“#{customerBean.name}"/> ! !! </h:form>!</h:body></html>!!! !!

§  JSF CustomerBean Attribute (1/3)

@ManagedBean @SessionScoped!public class CustomerBean implements Serializable {! private Customer currentCustomer;! ! public String getFirstname() {! return currentCustomer.getFirstname();! }! public void setFirstname(String firstname) {! currentCustomer.setFirstname(firstname);! }! public String getName() {...}! public void setName(String name) {...}!}!

§  JSF CustomerBean Audit Info (2/3)

@ManagedBean @SessionScoped!public class CustomerBean implements Serializable {!! @ManagedProperty("#{auth..Bean.authenticatedUser}")! private User currentUser;!!! public void setCurrentUser(User currentUser) {! this.currentUser = currentUser;! }!}!

Audit Info

§  JSF CustomerBean Update (3/3)

@ManagedBean @SessionScoped!public class CustomerBean implements Serializable {! @EJB! private CustomerService customerService;!! public String update() {! currentCustomer.! updateAuditInformation(currentUser);! ! customerService.updateCustomer(currentCustomer);! return Outcome.SUCCESS;! }!}!

Audit Info

§  CustomerService EJB

@Stateless!public class CustomerServiceEJB !

! !implements CustomerService {! ! @PersistenceContext! private EntityManager em;!! public Customer updateCustomer(Customer customer) {! return em.merge(customer);! }!}!! !!

CDI Optimierungspotential!?

CDI Refactoring

§  1 - CDI Wiring

§  2 - CDI Current User

§  3 - CDI Beans only

§  4 - CDI Style Formulare

§  5 - CDI Events

§  6 - CDI Ausblick

CDI Refactoring

eCustomer – CDI Wiring

§  JSR 330 Annotationen § @Named (für EL), @Qualifier

§ @Inject

§  JSR 299 Annotationen § @RequestScoped, @SessionScoped,

@ApplicationScoped, ...

@Named!@SessionScoped!public class AuthenticationBean! implements Serializable {!! ...!!}!!

§  JSF CustomerBean

@Named !@SessionScoped!public class CustomerBean implements Serializable {! ! @Inject // no EL support in @Named! private AuthenticationBean authBean;!! @Inject! private CustomerService customerService;!!}!

CDI Refactoring

§  Producer Methods/Fields §  Factory Method Pattern für fachliche

Objekte § @Produces

§ Qualifizierung über eigene fachliche Qualifier

eCustomer – CDI Current User

§  Current Qualifier

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

@Named @SessionScoped!public class AuthenticationBean! implements Serializable {!! private User authenticatedUser;! ! public String authenticate() {...}!! @Produces! @Current! public User getAuthenticatedUser() {...}!}!!

§  JSF CustomerBean

@Named @SessionScoped!public class CustomerBean implements Serializable {!! //@Inject // no EL support in @Named! //private AuthenticationBean authBean;!! public String update() {! // current.updateAuditInformation(! // authController.getAuthenticatedUser());! ! ...! }!}!

§  CustomerService EJB

@Stateless!public class CustomerServiceEJB !

! !implements CustomerService {! @Inject ! @Current! private User currentUser;! ! public Customer updateCustomer(Customer customer) {! customer.updateAuditInformation(currentUser);! return em.merge(customer);! }!}!! !!

Alternativ: JPA Event

Listener

CDI Refactoring

§  Injizierbare CDI Ressourcen § Normale Java Klassen

§ Optional mit @Named oder anderen Qualifier markiert

§  Enterprise Java Beans

§  Sonstige Java EE Ressourcen § PersistenceContext

§ UserTransaction §  ...

eCustomer – CDI Beans only

§  CDI CustomerService

// nothing required!public class CustomerServiceBean !

§  CDI CustomerService

// nothing required!public class CustomerServiceBean !

Transaktionen?!

§  Transactional Annotation

@InterceptorBinding!@Retention(RetentionPolicy.RUNTIME)!@Target({ElementType.METHOD, ElementType.TYPE})!!public @interface Transactional {! ! public TransactionalType value() !

!default TransactionalType.REQUIRED;! !}!

§  Transaction Interceptor*

@Transactional @Interceptor!public class TransactionInterceptor {!! @Inject! private UserTransaction utx;!! @AroundInvoke! public Object applyTransaction(!

! !InvocationContext ic) throws Throwable {!! // implement utx.begin(), utx.commit(), ...! } !}!

*XML registration omitted

§  Transactional CDI CustomerService

!public class CustomerServiceBean !

! !implements CustomerService {! ! @PersistenceContext! private EntityManager em;!! @Transactional ! public Customer updateCustomer(Customer customer) {! ...! }!}!! !!

§  Transactional JSF CustomerBean

@Named @SessionScoped!public class CustomerBean implements Serializable {!! @Inject! private CustomerService customerService;!!! @Transactional! public String update() {! ...! }!}!

CDI Refactoring

CDI Style Formulare

Und was hat CDI für die !Formularbehandlung im Angebot?!

CDI Style Formulare

§  CDI Conversations § @ConversationScoped

§ Conversation.begin()

§ Conversation.end()

§  JSF Backing Beans und Producer Methods § @Produces @Named

§ Qualifier

CDI Style Formulare

§  CustomerBean Conversation (1/2)

@Named @ConversationScoped!public class CustomerBean implements Serializable {! private Customer currentCustomer;! @Inject ! private Conversation conversation; !! public String selectCustomer(Customer customer) {! currentCustomer = customer;! conversation.begin();! ... ! }!}!

CDI Style Formulare

§  CustomerBean Conversation (2/2)

@Named @ConversationScoped!public class CustomerBean implements Serializable {!! public String update() {! conversation.end(); ! ...! }!}!

CDI Style Formulare

§  Achtung: Infrastruktur Teil des View

<html ...><h:body>! <h:form>! ! Vorname: <h:inputText ! value=“#{customerBean.firstname}"/>! Name: <h:inputText ! value=“#{customerBean.name}"/> ! ! </h:form>!</h:body></html>!!! !!

Infrastruktur!

CDI Style Formulare

§  JSF und Producer Methods

@Named @ConversationScoped!public class CustomerBean implements Serializable {! private Customer currentCustomer;!! public String selectCustomer(Customer customer) {! ... ! }!! @Produces ! @Named(“selectedCustomer“)! @Selected! public Customer getSelected() { ... } !}!

CDI Style Formulare

§  JSF und Producer Methods

<html ...><h:body>! <h:form>! ! Vorname: <h:inputText ! value=“#{selectedCustomer.firstname}"/>! Name: <h:inputText ! value=“#{selectedCustomer.name}"/> ! !! </h:form>!</h:body></html>!!! !!

CDI Refactoring

CDI Events

§  CDI Eventsystem §  Java EE Observer Pattern

§ Event Object

§ Event Producer § Observer Method

§  Eigenschaften § Schichtenübergreifend §  (Ggfs.) Transaktionsgebunden

§ Synchrone Interaktion

CDI Events

§  CDI Customer Created Event (1/3)

public class CustomerCreatedEvent {!! private Customer customer;!! public CustomerCreatedEvent(Customer customer) {...}!! public Customer getCustomer() { ... }!}!! !

CDI Events

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

CDI Events

@Inject! private Event<CustomerCreatedEvent> eventSource;!! public String createCustomer() {! Customer customer = ...;! ! eventSource.fire(! new CustomerCreatedEvent(customer)! );! ! ...! }!

CDI Events

Ist das Event Objekt wirklich notwendig?!

CDI Events

§  Qualified CDI Events (1/3)

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

CDI Events

public void sendWelcomeMail(! @Observes ! @Created ! Customer customer) { ! ! ...!}!!

CDI Events

@Inject! private Event<Customer> eventSource;!! public String createCustomer() {! Customer customer = ...;! ! eventSource! .select(new AnnotationLiteral<Created>(){})! .fire(customer);! ! ...! }!

§  Conditional Observer Methods §  Berücksichtigung von Transaktionen

(AFTER_SUCCESS, AFTER_FAILURE,...) und Bean Instanz Status (EXISTS,...)

public void sendWelcomeMail(! @Observes( ! receive=IF_EXISTS, // bean ! during=BEFORE_COMPETION // tx ! ) ! @Created ! Customer customer) { ... }!

CDI Events

CDI Refactoring

CDI Ausblick

§  CDI 1.1 § Declarative Transaktionen

§  Embedded Mode

§  Interceptor/Decorator Ordering

§  Static Injection

§  Spec Cleanup

§  ... §  Aufbau CDI Community

§  CDI Advocacy*

*https://sites.google.com/site/cdipojo/get-started

Java EE without EJB/Spring

Extensions Fazit

§  „Java SE Injection“

§  Scope System

§  Fachliche Dependency Injection

§  Infrastruktur und Businesslogik AOP

§  Eventmodell

§  Integrationsframework

§  CDI ermöglicht ... „Java Enterprise Development without EJB – and without Spring“

§  CDI bietet dafür... „typesafe und schichtenneutrales Injection Framework“ für fachliche und technische Injection sowie Rahmenwerk für eventgetriebene Entwicklung“

Gibt es noch Fragen?

Dann los ...

Java EE Development without EJB - and without Spring - Part 2

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