In Quest of Enterprise JavaBeans

摘要

There are some things about Web technology that make immediate sense to me, and others that don't. XML, the extensible Markup Language, falls into the former class. When I first read about it, its purpose seemed clear and its importance obvious. I suppose this is because so much of what I do professionally involves moving data from one incompatible format to another, and I've wished many times for a simple, standard syntax for moving objects out of databases and back in again. On the other hand, Enterprise JavaBeans (EJB) are in the latter class. Ever since I first encountered the term about six months ago, I've been trying to wrap my mind around the EJB concept, but somehow it keeps eluding me. Perhaps unsurprisingly, I've also been having difficulty understanding EJB's raison d'etre, the application server, and this despite an entire issue of Web Techniques devoted to the topic (February 1999). On the assumption that if I'm having trouble understanding EJB, then others are as well, I decided to look into the issue. What are Enterprise JavaBeans, what are they used for, and what should ordinary Webmasters know about them? In this article I'll report my discoveries back to you.