Getting Started with Roo

“You Win … a Braaand Neeew Web Application!”

Not really. Quite the opposite, actually. If you’ve been using Spring in web development before, then this application’s going to be very familiar. In fact, if you’ve ever written an application that’s as sophisticated and as large as the application that’s just been created for you, then you’re very familiar with these technologies, because you’ve no doubt spent a lot of time in front of them. So, nothing new about it. Just the familiar technologies you already know.

For those of you who haven’t seen an application that tackles as much as this one does, we’ll review some of the highlights.

Let’s look at what’s been configured in the web.xml. Roo has registered a listener—ContextLoaderListener—that is used to hoist Spring application contexts into existence. This is typically done to hoist into existence application contexts whose beans are visible to all other contexts. You might, for example, use this to start up the application context that contains your services, data sources, and other beans that might need to be shared across multiple other contexts.

Roo has registered the DispatcherServlet, which is of course the central class not only in Spring MVC, but Spring’s entire web stack. The DispatcherServlet can also hoist Spring application contexts into existence. You might register several DispatcherServlets in a single application—one for Spring MVC, one for Spring Web Services, etc., as your needs demand, so beans registered in an ...