1. Paul Statham Avatar Paul Statham
  2. Untitled project
  3. Oracle JSF Expert 1Z0-896

Wiki

Clone wiki

Oracle JSF Expert 1Z0-896 / Named Beans

View History

Advantages over JSF Managed beans

  • Allows for JEE wide dependency injection
  • POJOS can be injected
  • Can inject @Named beans into JSF beans
  • @ManagedProperty injection ONLY works inside a JSF @ManagedBean
  • Having getter and setter methods ISN'T required for @Named beans that are injected using @Inject

Using @Inject - javax.inject.Inject

Constructor injection

public class MyBean {

   private MyDependency dependency;

   @Inject
   public MyBean(MyDependency dependency) {
      this.dependency = dependency;
   }
}

Setter injection

public class MyBean {

   private MyDependency dependency;

   @Inject
   public void setDependency(MyDependency dependency) {
      this.dependency = dependency;
   }
}

Field injection

public class MyBean {

   @Inject   
   private MyDependency dependency;

}

Using @PostConstruct - javax.annotation.PostConstruct

CDI calls the method after all injection has occurred and after all initializers have been called.

@Named
public class CustomerBean {

   @Inject
   private CustomerService customerService;

   private List<Customer> customers;

   @PostConstruct
   public void init() {
      customers = customerService.findAll();
   }

}

Using @PreDestroy - javax.annotation.PreDestroy

Used for example to release resources before destroying a bean

/**
 * Admittedly a contrived example
 */
@Named
public class MyBean {

   private InputStream inputStream;

   @PostConstruct
   public void init() {
      // Open input stream for reading from
   }

   @PreDestroy
   public void destroy() {
      // Close input stream before destroying bean
   }

}

Updated