Middleware Matters

Don's already mentioned it, but my July/August Internet Computing (IC) column is now available, either as PDF or on the Distributed Systems Online site. This column covers Java Business Integration (JBI, aka JSR 208).

In the context of JBI, Don asks about containers. My take is that containers aren't as special as we'd like to think they are. A container really just supports a particular programming model or style. Some do this by forcing certain inheritance structures, others do it by providing particular service APIs, still others state via some sort of contract what they expect of things that they contain. Most use a combination of these approaches. A good container handles the tedious or error-prone details of a particular approach, letting developers focus on their business logic. Containers have been around for decades and won't disappear anytime soon. Writing good containers is pretty hard. Therefore, rather than seeking the "one true container," we should allow for and support container diversity. In fact, isn't that what the web services approach helps with, given that it focuses on the message rather than imposing rules for how applications that handle such messages must be built?