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... (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 shoul... (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... (more)

Transactions and Exception Handling in EJB 1.1

Many of you have been developing EJB applications since the 1.0 version of the specification. In the EJB 1.1 specification the approach toward EJB exception handling has changed slightly regarding the exceptions and transaction management responsibilities between bean providers and container vendors. Those of you who made the conversion from 1.0 to 1.1 may not have enjoyed this "tighten... (more)

XML DTD for EJB Deployment Descriptors

To those of you familiar with Enterprise JavaBeans (EJB), deployment descriptors are nothing new. Essentially, a deployment descriptor's purpose is to collect declarative information that can be modified during deployment of an enterprise bean. Deployment descriptors are a key element in the component-based development capabilities of EJB. They allow users to modify, link and deploy EJB ... (more)