EJB Section Index | Page 7

Hi, When you execute a lookup to get the home interface of your bean, you normally use the lookup() method of the javax.naming.Context interface. This method will return you an Object that needs t...more

According to Richard Monson Haefel's book (Enterprise Java Beans, O'Reilly), Stateful Session Bean conceptually doesn't have instance pooling. But some container implement pooling internally. Acc...more

The short answers are: No and Yes. A SystemException is a subtype of java.lang.RuntimeException, while an ApplicationException is any Exception that does not extends neither java.lang.RuntimeExce...more

Check out the Java Developer Connection of Sun's Java web site. There is a very interesting article, written by Beth Stearns: Enterprise JavaBeans 2.0 Container-Managed Persistence Example.more

Referring article: http://servlet.java.sun.com/javaone/javaone2000/pdfs/TS-1295.pdf Static variables are only ok if they are final. If they are not final, they will break the cluster. What that m...more

To have a consistent interface, so that there is no different interface that you need to implement for Stateful Session Bean and Stateless Session Bean. Both Stateless and Stateful Session Bean im...more

Stateful Session Bean A stateless session bean has only two states: Does Not Exists and Method Ready Pool. A bean has not yet instantiated (so it is not an instance in memory) when it is in the Do...more

From the EJB 2.0 specification: "An onMessage call is always a separate transaction, because there is never a transaction in progress when the method is called." When a message arrives, it is pas...more

Does scalibility means supporting mulitiple concurrent users alone? Scalability means that the performance of the application does not deteriorate greatly as more users are connected to the syste...more

Question continues: What are all the changes I have to do for my EJB1.1 code to port into EJB2.0 compatible. The present application is in EJB1.1. I need to port this code to EJB2.0 spec. Ejb 1.1...more

javax.naming.Context is an interface that provides methods for binding a name to an object. It's much like the RMI Naming.bind() method. javax.naming.InitialContext is a Context and provides imp...more

EJB-JNI-Legacy Integration(C++ API) We have exisitng System in C++.We want to use Existing in the intranet/internet. We are using JNI to use existing System. And then we are calling JNI Classes i...more

I think you can. As far as I know, there is nothing, in the EJB specifications, that prevents you to create an Entity Bean without the create() method. In this situation, the only way to obtain an...more

CMP 2.0 entity bean. Can I write a method in CMP 2.0 Entity Bean which can retrieve some data from database (ie. is it possible to have a CMP entity bean mapped to a particular table and have a bus...more

Hi, In a few words, I would say that the main reason is because there is a clear division of roles and responsabilities between the two interfaces. The home interface is your way to communicate wi...more