How does passivation work in stateful session beans?
Unlike entity beans and stateless session beans, stateful session bean are usually evicted from memory when they are passivated. This is not true of all vendors... Read more »
‘EJB Interview Questions’ - KyaPoocha.com
Are Enterprise JavaBeans and JavaBeans the same thing?
Enterprise JavaBeans and JavaBeans are not the same thing; nor is one an extension of the other. They are both component models, based on Java, and created by Sun... Read more »
Why an onMessage call in Message-driven bean is always a separate transaction?
EJB 2.0 specification: “An onMessage call is always a separate transaction, because there is never a transaction in progress when the method is called.”... Read more »
Can I develop an Entity Bean without implementing the create() method in the home interface?
As per the specifications, there can be ‘ZERO’ or ‘MORE’ create() methods defined in an Entity Bean. In cases where create() method... Read more »
What is the need of Remote and Home interface. Why can’t it be in one?
The main reason is because there is a clear division of roles and responsibilities between the two interfaces. The home interface is your way to communicate... Read more »
What is the advantage of putting an Entity Bean instance from the Ready State to Pooled State?
The idea of the Pooled State is to allow a container to maintain a pool of entity beans that has been created, but has not been yet synchronized or assigned... Read more »
Does the container create a separate instance of the generated EJBHome and EJBObject classes?
The EJB container maintains an instance pool. The container uses these instances for the EJB Home reference irrespective of the client request. While referring... Read more »
Does RMI-IIOP support code downloading for Java objects sent by value across an IIOP connection in the same way as RMI does across a JRMP connection?
Yes. The JDK 1.2 supports the dynamic class loading. The EJB container implements the EJBHome and EJBObject classes. For every request from a unique client, Read more »
What is a Message Driven Bean, what functions does a message driven bean have and how do they work in collaboration with JMS?
Message driven beans are the latest addition to the family of component bean types defined by the EJB specification. The original bean types include session... Read more »
For Entity Beans, What happens to an instance field not mapped to any persistent storage, when the bean is passivated?
The specification infers that the container never serializes an instance of an Entity bean (unlike Stateful session beans). Thus passivation simply involves... Read more »
Is method overloading allowed in EJB?
Yes you can overload methods should synchronization primitives be used on bean methods? - No. The EJB specification specifically states that the enterprise... Read more »
What is an EJB Context?
EJBContext is an interface that is implemented by the container, and it is also a part of the bean-container contract. Entity beans use a subclass of EJBContext... Read more »
How is persistence implemented in enterprise beans?
Persistence in EJB is taken care of in two ways, depending on how you implement your beans: container managed persistence (CMP) or bean managed persistence... Read more »
What is the difference between a Server, a Container, and a Connector?
An EJB server is an application, usually a product such as BEA Weblogic, that provides (or should provide) for concurrent client connections and manages system... Read more »
How can I call one EJB from inside of another EJB?
EJBs can be clients of other EJBs. It just works. Use JNDI to locate the Home Interface of the other bean, then acquire an instance reference, and so forth. Read more »