Jason Westra

Several patterns exist for generating primary keys for your EJB application. This month I'll provide a pattern for generating PKs that's scalable, generic, and portable. My format for defining the pattern will follow the catalogued layout presented in the Gang of Four book, Design Patterns: Elements of Reusable Object-Oriented Software. Pattern: UniqueID Generator Intent: Generate unique IDs for persistent objects in an EJB application Also Known As: PID (Persistent ID) Factory GUID (Globally UniqueID) Manager Motivation Enterprise JavaBeans is a server-side component model that targets the specific business domain of online transaction processing (OLTP) applications. OLTP applications generally have the need to store information persistently. The data records or objects for each transaction require unique identifiers to allow them to be stored and retrieved accurate... (more)

Interview...with Paul Chambers

JDJ: Paul, I'd like you to give us some technology trends and talk a little bit about GemStone's role in the wireless market. Tell us some of the key players in that market right now. Chambers: The wireless market is a little bit different for people in software and it's been driven, really, by the telecommunications industry, which makes it a bit different. I think that if your name is on the play list, you can see where it's going to go within the next few years. The sorts of players that you've got in the market are telecommunications equipment manufacturers and the northern m... (more)

BEA Web Services

It is the dawn of a new season as BEA WebLogic Developer's Journal moves into its second year. What better way to start the new year than with a focus issue on Web services? And it's not too early to do so; as we move closer to BEA's eWorld 2003 developer conference in March, I'm sure Web services will be a hot topic. Before drafting this month's editorial, I sat down and really thought about what makes Web services compelling to me. I thought this through in numerous "contexts." The two I put myself into are those of a consumer and an application architect. Our current context ... (more)

Managing Complexity of J2EE

There's no question about it - J2EE applications are tough, burly pieces of software. Often they require numerous servers, communicate over various protocols, and run on software from various vendors. Let's examine a simple J2EE application in which everything, including the database, runs on one machine. In this case, the Web server and application server are a single instance of WebLogic, and the database is the one bundled with your version of WebLogic. Sounds pretty easy to manage, right? You just put your applications in the /applications directory and WebLogic deploys them... (more)

How to Develop Message-Driven Beans

This month in EJB Home I'll show you how to build a message-driven bean. Knowledge of this EJB will enhance your toolkit for developing asynchronous Enterprise Java applications - whether they're mission-critical or not. The Enterprise JavaBeans specification 2.0 introduced another bean into the mix. One of the primary goals for the EJB 2.0 release was to define how EJB interacts with the Java Message Service (JMS), thereby defining how these Enterprise Java APIs interact within the Java 2 Enterprise Edition (J2EE) platform. Until version 2.0 of the specification was released, the... (more)