Raghu R. Kodali

We've all heard about the simplicity and power of the EJB 3.0 specification. And because this has proven to be true, we can't help but think that performance must be rather poor. After all, all that simplicity must come at a price. With this in mind, we set out to test EJB 3.0's performance using Oracle's implementation of the specification. Although the implementation we used is a developer preview, where the focus is typically on product stability instead of performance, our expectations are that the performance will be below or in the best case the same as previous versions of the EJB specification. We thought that the best way to test was to do a few things that developers typically do with EJB 2.1 and then try out the equivalent with EJB 3.0. This would let us compare performance rather than deal with raw numbers that probably wouldn't mean much. We tested the ... (more)

Java Feature — Inheritance Hierarchies in JPA

The persistence model introduced in EJB 3.0 as a replacement for entity beans is known as the Java Persistence API (JPA). The JPA borrows from both proprietary and open source models, such as Oracle TopLink, Hibernate, Spring, and other frameworks, which have gained traction as popular alternatives to the often heavyweight and cumbersome persistence directives required by earlier EJB revisions. Among the new features introduced in EJB 3.0 through the JPA is support for entity inheritance. In this article, we will examine inheritance strategies supported by the JPA and apply these... (more)

EJB 3 Transactions

Much of the work surrounding the design and development of enterprise applications involves decisions about how to coordinate the flow of persistent data. This includes when and where to cache data, when to apply it to a persistent store (typically the database), how to resolve simultaneous attempts to access the same data and how to resolve errors that might occur while data in the database is in an inconsistent state. A reliable database is capable of handling these issues at a low level in the database tier, but these same issues can exist in the middle (application server) an... (more)

The Simplicity of EJB 3.0

Over the past few years, the Enterprise JavaBeans (EJB) specification has evolved significantly. In the early days of EJB, application developers faced a burden of overwhelming complexity: they had to manage several component interfaces, deployment descriptors, and unnecessary callback methods; work within the limitations of the EJB Query Language (EJBQL); and learn and implement the design patterns used to overcome the limitations of the specification. The introduction of the EJB 2.1 specification did improve things, although many still say the specification is too complex - an... (more)

Asynchronous Web Services Using WS-Addressing

Today's IT organizations have tens of applications and services that perform some well-defined tasks such as inventory, billing, expense reporting, and order entry. With the evolution of Internet and e-business, enterprises have started to think about how different applications in a disconnected mode can work independently but at the same time be a part of an information workflow process. This new demand brought us to the concept of building new applications and integrating them with existing ones. Integrating new and old applications becomes a very complex task, because of both... (more)