EJB Interview Questions 

EJB Interview questions with answers

Explain EJB in brief. Answer - EJB is a standard for developing server side in JAVA..... What are the kinds of EJB's? Answer - There are 3 kinds of EJB's - Session beans, Entity Beans, Message-driven beans... What is Passivation and activation in EJB? Answer - In case of stateful session beans, we need to store the client conversation.... Describe the life cycle for stateless and Stateful beans. Answer - Between the client and the session bean, the state of the conversation can be maintained using a stateful session......... EJB Interview - August 1, 2008, 11:35 am by Amit Satpute Define EJB QL? Answer - EJB QL stands for Enterprise Java Beans - Query Language. It was introduced in the EJB 2.0..... What is an EJB Context? Answer - EJBContext is an interface implemented by the container. It is a part of the bean-container contract..... List out the difference between EAR, JAR and WAR file? Answer - Modules are packaged based on their functionality as EAR, JAR and WAR files....... What is lazy loading? Answer - Heavy weight application consume a lot of time while loading the plug-ins. In lazy loading...... Define Session Bean? Answer - Session beans are used to shield the client from the complexity of the business logic...... What is a Stateful Session bean? Answer - Between the client and the session bean, the state of the conversation can be maintained using a stateful..... What is stateless session bean? Answer - A stateless session bean is an enterprise bean that does not maintain conversational state specific to a client session...... Explain create methods of Entity Bean? Answer - The create() method is used to insert data into the database by creating a new ..... What happens if remove( ) is never invoked on a session bean? Answer - Two situations need to be taken under consideration:..... Explain the default transaction attribute for an EJB? Answer - There is no default transaction attribute for an EJB. The deployer must specify..... List out the difference between a Server, a Container, and a Connector? Answer - A server is an application that responds to the requests made by client(s) and manages.... Explain why is ejbFindByPrimaryKey mandatory. Answer - Primary Keys are used to uniquely identify objects from a database. The ejbFindByPrimaryKey method..... Define session façade. Answer - The SessionFacade is implemented as a session bean. It acts like a wrapper class..... What is the difference between CMP and BMP? Answer - CMP (Container-managed Persistence) BMP (Bean-managed Persistence)..... What are transaction isolation levels in EJB? Answer - Transaction_read_uncommitted- Allows a method to read uncommitted data from a DB(fast but not wise)..... What is bean managed transaction? Answer - To increase the productivity, database operations can be implemented manually by writing suitable..... What is abstract schema? Answer - Abstract schema is specified for entity beans with container managed persistence. The name..... What is Message Driven Bean? Answer - A Message Driven Bean is a message consumer. Message-driven beans receive JMS...... What is Deployment descriptor? Answer - The deployment descriptor directs a deployment tool to deploy a module or application...... Is it possible to invoke Runtime.gc() in an EJB? Answer - The call will most likely be ignored.......