1. Distributed object infra structure.
2. Component packing add employment.
3. Declarative transaction management.
4. Factory support.
5. Bean activation and passivation.
6. Container metadata.
7. Security.

i)  Distributed object infrastructure:

EJB does not concern itself with the distributed object infrastructing. It assumes underlying ORB that understands the CORBA RMI/IDI. Semantics. The ORB transports must be able to propagate CORBA OTS transactions. IIOP ORB’s are designed to provide this type of service.

ii) Component packaging and deployment :

EJB defines a packaging mechanism for Server-side components based on JAR’s manifests and deployment descriptors. The container un-JAR’s the EJB and then runs if based on the instruction it gets from the maifest and deployment descriptors.

iii) Declarative transaction Management :

EJB supports implicit transaction built on the CORBA OTS/JTS services. EJB does not need to make implicit calls to OTS/JTS to participate in distributed transaction. The EJB container automatically manges the start, commit and roll back of a transaction. Programming can define the transactional attribute of a bean at design time using declartive statement in deployment descriptor. Metadata about the beans they contain, for example, the container can return the class name of the Enterprise bean that this factory interface is associated with.

iv) Factory Support :

As a bean provides programmer is responsibel for defining a remote factory interface for bean. Developer define a factory I/F that extends factory and define one or more create method. The container provider will automatically generate the factory implementation.How ever, bean must implement an EJB  create() for each create(). As a last step, programmer must register factories with the container, so, that client can create new beans. The container also provide a finder interface to help clients locate existing entity bean.

v) Bean activation and passivation:

As a part of managing the life cycle of an enterprise bean the container calls your bean when it is loaded into memory(or activation). It also calls it when it is deactivated from memory for passionate.

vi) Bean state management :

EJB container can handle both transient and persistent bean. Persistent bean encapsulate in their object reference a unique ID that point to their state. An entity bean manages its own persistence by implementing the persistencde operation directly the container simply hands it a unique-key and tells it to load its state.

vii) Container Metadata

EJB containers can provide metadata about the beans they contain. For example the container an return the class name of the enterprise bean that  this factory interface is associated with.

viii) Security :

EJB cotainer automate the management of some of the security aspects of a bean . Programming needs to declaratively define the security rules for an enterprise bean in security descriptor object. Programmer must then serialize this object and put it in the beans JAR. The EJB container uses this object to perform all security check on behalf of bean.

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