Delivering Enterprise JavaBeans
Building and Deploying a Polling Application with EJB
By Tom Spitzer and Jack Hakim
An Enterprise JavaBean (EJB) is a server-based Java component that you build and deploy according to Sun's Enterprise JavaBean specification. To deploy applications that include EJB components, you must install a server that offers EJB support in compliance with the specification. Such a server must provide an EJB container mechanism. Web Techniques has covered application-server products in previous issues; many of these products, including BEA Weblogic, IBM WebSphere, Persistence PowerTier, and Novera jBusiness4, have added EJB container support. (See "
Online" for URLs.)
EJB offers an extremely promising mechanism to develop and deploy distributed business components. When we took a hard look at the EJB component model and how it was being supported in the software community, we saw a number of contradictions. On the one hand, EJB promises a consistent development model and a high degree of portability. On the other, evolution of the EJB specification has been slow. Some key vendors have taken a wait-and-see attitude, while others have implemented EJB support in a manner that binds developers to their application server products. Both the slow introduction of development tools with strong support for EJBs and developer confusion over how EJB fits into the Java API alphabet soup have delayed adoption of this technology. Against that backdrop, developers have stuck with other server-side Java deployment techniques that include developing components with custom interfaces and using servlets.<>
