Interview Questions and Answers

Are you a developer? Need to update your software development knowledge or need to prepare for a job interview? Check out this collection of interview questions and answers...

EJB Interview Questions and Answers - -

• What is EJB?
• What is session Facade?
• What is EJB role in J2EE?
• What is the difference between EJB and Java beans?
• What are the key features of the EJB technology?
• What are the key benefits of the EJB technology?
• How many enterprise beans?
• What is message-driven bean?
• What is Entity Bean and Session Bean ?
• How EJB Invocation happens?
• Is it possible to share an HttpSession between a JSP and EJB? What happens when I change a value in the HttpSession from inside an EJB?
• The EJB container implements the EJBHome and EJBObject classes. For every request from a unique client, does the container create a separate instance of the generated EJBHome and EJBObject classes?
• Can the primary key in the entity bean be a Java primitive type such as int?
• Can you control when passivation occurs?
• What is the advantage of using Entity bean for database operations, over directly using JDBC API to do database operations? When would I use one over the other?
• What is EJB QL?
• Brief description about local interfaces?
• What are the special design care that must be taken when you work with local interfaces?
• What happens if remove( ) is never invoked on a session bean?
• What is the difference between Message Driven Beans and Stateless Session beans?
• How can I call one EJB from inside of another EJB?
• What is an EJB Context?
• Is is possible for an EJB client to marshal an object of class java.lang.Class to an EJB?
• Is it legal to have static initializer blocks in EJB?
• Is it possible to stop the execution of a method before completion in a SessionBean?
• What is the default transaction attribute for an EJB?
• What is the difference between session and entity beans? When should I use one or the other?
• Is there any default cache management system with Entity beans ?
• Why is ejbFindByPrimaryKey mandatory?
• Why do we have a remove method in both EJBHome and EJBObject?
• How can I call one EJB from inside of another EJB?
• What is the difference between a Server, a Container, and a Connector?
• How is persistence implemented in enterprise beans?
• What is an EJB Context?
• Is method overloading allowed in EJB?
• Are we allowed to change the transaction isolation property in middle of a transaction?
• For Entity Beans, What happens to an instance field not mapped to any persistent storage, when the bean is passivated?
• What is a Message Driven Bean, what functions does a message driven bean have and how do they work in collaboration with JMS?
• 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?
• Does the container create a separate instance of the generated EJBHome and EJBObject classes?
• What is the advantage of putting an Entity Bean instance from the Ready State to Pooled state
• Can a Session Bean be defined without ejbCreate() method?
• Is it possible to share an HttpSession between a JSP and EJB? What happens when I change a value in the HttpSession from inside an EJB?
• Is there any way to read values from an entity bean without locking it for the rest of the transaction (e.g. read-only transactions)?
• What is the difference between a Coarse Grained Entity Bean and a Fine Grained Entity Bean?
• What is EJBDoclet?