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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 called EntityContext. Session beans use a subclass called SessionContext. These EJBContext objects provide the bean class with information about its container, the client using the bean and the bean itself. They also provide other functions....
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What is the difference between ejbCreate() and ejbPostCreate()
Answered by Jey on 2005-05-08 11:14:33: Session and Message Driven Bean will have only ejbCreate() method and no ejbPostCreate() method. Entity bean will have both ejbCreate() and ejbPostCreate() methods. The ejbPostCreate method returns void, and it has the same input parameters as the ejbCreate method. If we want to set a relationship field to initialize the bean instance, we should do...
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Just by seeing the signature of the bean how can you specify whether it is a Stateful or Stateless Session Bean?
upendar_qtp
- Mar 20th, 2006
u can just check the home interface of the session bean in order to detemine the whether it is stateless or stateful.if there is single create method in home interface with no argument then we can say...
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1. How EjbQL ara impemented when it is necessary?2. what do you mean by shared transactional state data maintained by EJB?3. what do you mean by CMP & BMP & what is basic difference between them?4. where are databese maneged by Entity bean is implemented & how many instance of the Entity beanfor each client is maintained by Ejb container?please describe ths question conceptually?5. why BMP class returns null & why CMP implementation class reurns instanceof PK class?6. what do you mean by EJB client & EJB Server ?7. where home interface resides?remote mechine or client machine?8. How ejb,jsp,Oracle communicates in building a business Application?9. why we need the transactions?10. What is an EJB Context?
s_s78
- Mar 20th, 2006
A1. EJB QL is introduced in EJB 2.0 specification it is used to write only finder(Select) queries for Entity beans. it is simple to write and give OO feel. it supports lazy loading.A2.It is only appli...
ravikantiramu
- Mar 7th, 2006
Ejb Context is the container implemented object....Using this object....We can get the information about the bean,and check the user role and find the transaction status.........
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When should we use session bean/entity bean?I was unable to judge?For Example :For Airline Project where we can use EJB\'s?How can we differentiate the stateful and stateless session beans?
s_s78
- Mar 20th, 2006
Session bean has business logic and database operation methods.Entity bean's one feature is to make your application database independent. means if you change database,tables u need not to see code written in your session bean u just need to edit very few line in you entity DD files.
antony
- Jan 14th, 2006
Thanks vemodher.... Good answer
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Where is JNDI located (In client or server).If its server, how a client can get the information about whichEJB is registered in JNDI ?.How EJB will be registered in JNDI.
ak40732
- Mar 23rd, 2006
JNDI is a service which is offered by the servers like Weblogic etc.We can make any business or entitiy components which are reusable across different applications to be available to any type of clien...
s_s78
- Mar 20th, 2006
client must know JNDI name of EJB before looking for it it will go through RMI-IIOP protocol.and lookup is performed by container
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What is session synchronization in EJB
rkj2ee2005
- Mar 25th, 2006
It is used for transaction support in stateful session beans. EJB container calls call back functions on sfsb (if it implements SessionSynchronization interface) after transaction started, before completion and after completion.Bean developer can do house keeping stuff in these methods.
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When do we use entity beans in a project and when do we use the different types of entity beans
hmashruf
- Apr 7th, 2006
To add, in CMP container handles queries to database and so it is good when interacting/deploying in various database environments.While in BMP bean developer has to write SQL queries to load and...
somu chowdareddy
- Oct 4th, 2005
Maintain the persistance in database side.
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Can a Session Bean be defined without ejbCreate() method
Answer posted by Mohan on 2005-05-21 19:27:35: No
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How many JVM's can we run in a system?
we can run any number of JVM's.
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How can i maintain a user session b/w servlets and stateful session ejbs? (both are on different layers i.e web layer and EJB layer
mailtorkthakur
- Apr 20th, 2006
Just save the sessionbean object in your servlet session and retrive it when required.
Rakesh
- Apr 20th, 2006
Just save the sessionbean object in your servlet session and retrive it when required.
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How can we manage transactions in ContainerManagedTransaction beans?
mailtorkthakur
- Apr 20th, 2006
You can configure your container to do so. You can also use setRollbackOnly,getRollbackOnly methods. If such a requirement opt for BMP.
Rakesh
- Apr 20th, 2006
You can configure your container to do so, but you can not do it you self. If such a requirement opt for BMP.
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How to deploy EJB without using GUI in different servers(e.g weblogic,jboss etc)
mailtorkthakur
- Apr 20th, 2006
It is not mandatory to create EAR to deploy EJB. You can just create a JAR file with all dependancy resolved. There no generic way to deploy EJB on different server, Every server has it's own deployment process. So just follow the deploment steps of your server.
Prasanna Balaraman
- Dec 16th, 2005
The first step is to create EAR file, which contains both WAR, JAR files with application.xml. For Jboss:Really it is simple just copy the EAR file to the [server\default\deploy] deploy folder. For We...
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