How do Java EE 6 Bean Annotations Differ for Managed Beans, Dependency Injection, and Lifecycle Management?

Understanding the Differences between Java EE 6 Bean Annotations

In Java EE 6, several sets of annotations are available for creating managed beans, injecting dependencies, and managing their lifecycle:

• EJB Annotations: @Stateful, @Stateless

  • Used for creating Enterprise JavaBeans (EJBs), which provide distributed component models and transaction management.

• javax.annotation.ManagedBean:

  • An older annotation used for creating managed beans.
  • Deprecated in favor of CDI managed beans and EJBs.

• javax.faces.ManagedBean, @SessionScoped, @RequestScoped:

  • Annotations specific to JavaServer Faces (JSF) managed beans.
  • Used for defining beans with different scopes within JSF applications.

• javax.enterprise.context.SessionScoped, @RequestScoped:

  • Annotations used by Context and Dependency Injection (CDI) managed beans.
  • Define the scope of CDI beans within an application.

• javax.inject.Named, @Inject:

  • Annotations used by CDI beans.
  • @Named identifies a bean for injection, while @Inject specifies the dependency to be injected.

Relationships and Usage

CDI managed beans are the primary dependency injection and bean management framework in Java EE 6. CDI beans integrate with EJBs, allowing EJBs to be injected into CDI beans and vice versa.

JSF managed beans are specific to JSF applications. They can be used within JSF pages, but their scope and functionality are limited compared to CDI beans.

Injecting Dependencies

• @EJB: Used to inject EJBs into EJBs or CDI beans.
• @Inject: Used to inject CDI beans into other CDI beans or into EJBs.
• @ManagedProperty: An older annotation used for injecting beans into EJBs or JSF managed beans. It is deprecated in favor of @Inject.

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