EJB Section Index | Page 2
EJB is scalable because it can run in cluster environment. What is there in EJB specification and in Application Server that supports this feature ?
EJB and scalability EJB is scalable because it can run in cluster environment. What is there in EJB specification and in Application Server that supports this feature ?
Synchronization of Stateless Session bean instances. Is there anyway by which we can update/modify (not on server start up but at actual application run time) value of instance variables of ll stateless session bean instances present in the pool??
Additional Note This is something related to snchronizing all the instances. If a user modify a variable in Stateless Session Bean can it be reflected to all other instances in the pool? so that ...more
Compared to the 2.0 specifications, EJB 2.1 have focused the attention in trying to be more "web-services" oriented, and with the improving of some important features where the community have foun...more
From a logical point of view, a Servlet/JSP session is similar to an EJB session. Using a session, in fact, a client can connect to a server and maintain his state. But, is important to understan...more
why we use home interface in EJB. In RMI we dont have any concept like home interface.why we particularly go for Home Interface Both RMI and EJB are distributed applications. In EJB we use Home interface which is not avaliable in RMI. There must be several reasons for using Home Interface of EJB. can any one give reason for this?
By posing this question, you seem to be comparing RMI and EJB as if they were the same type of technology and they are definately not. RMI is a lower level technology that allows java objects to b...more
JDO is a persistence technology that competes against entity beans in enterprise application development. It allows you to create POJOs (plain old java objects) and persist them to the database - ...more
There is absolutely no relationship between the amount of EJBObjects you create on the client side and the amount of bean instances that actually exist on the server side. When a client invokes a ...more
Can JavaMail be used from a Message Driven Bean? The EJB specifictation requires that the bean implementation must be single-threaded. Isn't JavaMail multi-threaded? If so, can it be used from a Message Driver Bean?
You should configure a JavaMail resource for your EJB container and access it by JNDI. It works just like JavaMail in an application without setting up the connection first. You just get it from t...more
First, let's say that the way in which you do this will vary depending on whether you are using an Entity Bean or a Session Bean. The way in which you access your database from an Application Ser...more
There are many differences, all of them should give different type of advantages among the previous 1.1 version. New CMP Model. It is based on a new contract called the abstract persistence schem...more
Session facade is one design pattern that is often used while developing enterprise applications. It is implemented as a higher level component (i.e.: Session EJB), and it contains all the iteract...more
Session Bean transactions. Why EJB 1.1 specs says that Session Beans can have BM or CM transaction, but not both in same bean?
CMTs and BMTs are 2 different animals. Mixing them in the same bean would require the application container to potentially start a transaction at the beginning of the method while the BMT bean its...more
The main difference is that in EJB 2.0, the persistence manager is responsible for mapping the entity bean to the database based on the newly introduced abstract persistence schema. In other words...more
Whats the intention behind doing this? What kind of EJB's are u talking about? In any case, I dont think such kind of functionality is provided ready made by any application server. Some may prov...more
In theory, you should not need any tools for that task. If you have developed a fully compliant J2EE application, you will be able to deploy it on any Application Server that follows Sun J2EE Spe...more