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)

Developing Coarse Grained Business Components

Discussion groups have recently been abuzz with talk of "coarse-grained entity beans" - a slight misnomer deriving, I suspect, from the addition of mandatory entity beans in EJB 1.1. This month I'll examine the finer points of the Enterprise JavaBeans specification regarding coarse-grained entities, as well as my own, and provide an example for you - with plenty of comments to provide food for thought when you tackle the challenge yourself. For those of you who finally came out of your Y2K shelter, EJB is a specification for building server-side business components on the Java p... (more)

Implementing J2EE Security With WebLogic Server

In the March issue of JDJ (Vol. 6, issue 3) we discussed the basics behind J2EE security, including coverage of role-based security for both the Web and EJB tiers. In Part 2, we provide an example of implementing J2EE security in the WebLogic Server. While this article and the examples contained within are specific to WebLogic 6.0, all of the deployment code and standard descriptors should be portable to any J2EE-compliant server. We won't cover encryption and SSL this month, as they're articles in their own right. Trader Application How many securities trading examples have you ... (more)

Securing Your Company Data with EJBs

Often we think of security as a burden, a time-consuming process that requires us to jump through hoops just to get through a doorway or view a Web page on the company intranet. My first real appreciation for (or frustration with) security came a number of years ago. I was a PowerBuilder consultant in Minneapolis, helping the Federal Reserve Bank build its first-ever client/server application. Each day it was a hassle just to get past the security desk in the lobby, and the bombing of the World Trade Center in New York that year did nothing to ease the pain. My next interesting ... (more)

The Business Advantage of EJB: Part One

What's all this hype about portability? Portability has been a hot topic since Java's arrival just a few years ago, so I'm going to devote some space toward understanding portability issues centered around the Enterprise JavaBeans architecture and development. This month I'll discuss the various types of portability and Java's relationship to each; then I'll touch on the portability goals of the EJB specification and where EJB portability lacks maturity (and why not to worry). Next month I'll provide tips on EJB portability as well as code examples depicting how you can help achi... (more)