EJB Interview Questions and Answers
Question - 81 : - Differentiate Conversational from Non-conversational interactions?
Answer - 81 : -
The interaction between the client and the bean is called conversational while where multi method conversations are not held with clients it is known as non-conversational interactions.
Question - 82 : - Define ejb Create() and EjbPostCreate ()?
Answer - 82 : -
When the method is called before the persistence storage is written with the bean state, it is ejbCreate ().
When the method is called after the persistence storage is written with the bean state, it is ejbPostCreate ().
Question - 83 : - Define EAR, WAR and JAR ?
Answer - 83 : -
JAR files contain all EJB classes.
WAR files contain all servlets, web component pages, gif, html, beans, applets, classes and classes.
EAR files contain both JAR and WAR files.
Question - 84 : - Differentiate Phantom from Un-repeatable?
Answer - 84 : -
When data that did not existed before is inserted, it is read as phantom whereas when data that already existed is changed, un-repeatable occurs.
Question - 85 : - Define ACID Properties?
Answer - 85 : -
ACID is Atomicity, Consistency, Isolation and Durability.
- Atomicity: Operations that are bundled together and projected a single unit of job.
- Consistency: Guarantees that after a transaction has taken place, there will be consistency.
- Isolation: Helps protect viewing of other simultaneous incomplete transaction results.
- Durability: Ensures durability by keeping a transitional log by which the permanent data be recreated by again applying the steps involved.
Question - 86 : - What do you mean by ‘Hot deployment’ ?
Answer - 86 : -
The act of redeployment, deployment and un-deployment in Web logic when the server is running in EJB is called Hot Deployment.
Question - 87 : - How can a session bean be configured for transactions of bean-managed?
Answer - 87 : -
It can be done by setting transaction-attribute in the deployment sector or XML file.
Question - 88 : - Enlist the technologies embraced in J2EE.
Answer - 88 : -
The technologies embraced in J2EE are:
- Enterprise JavaBeansTM (EJBsTM)
- JavaServer PagesTM (JSPsTM)
- Java Servlets
- The Java Naming and Directory InterfaceTM (JNDITM)
- The Java Transaction API (JTA)
- CORBA
- The JDBCTM data access API.
Question - 89 : - What do you mean Enterprise JavaBeans (EJB) container?
Answer - 89 : -
Enterprise JavaBeans container helps in managing the implementation of enterprise beans applications of J2EE.
Question - 90 : - What do you mean by in-memory replication?
Answer - 90 : -
When the contents having the memory of a single physical m/c are simulated in all m/c in that cluster, that process is called memory replication.