Head First Servlets and JSP, 2nd Edition

What goes where in a web app

In several chapters of this book, we’ve looked at the locations in which the various files must be placed. In the chapter on custom tags, for example, you saw that Tag Files must be deployed in /WEB-INF/tags or a subdirectory, or in a JAR file under /META-INF/tags or a subdirectory. If you put a Tag File anywhere else, the Container will either ignore it or treat it as static content ready to be served.

The Servlet and JSP specs have a lot of picky rules about where things go, and you really do need to know most of them. Since we’ve already covered most of this in one way or another, we use these first few pages as a test of your memory and understanding. Don’t skip it! Treat these next few pages as practice exam questions!

There are no Dumb Questions

Q:

Q: Why should I have to know where everything goes... isn’t that what deployment tools are for? Or even an ANT build script?

A:

A: If you’re lucky, you’re using a J2EE deployment tool that lets you point and click your way through a series of wizard screens. Then your Container uses that info to build the XML Deployment Descriptor (web.xml), build out the necessary directory structures, and copy your files into the appropriate locations. But even if you are lucky, don’t you think you need to know what the tool is doing? You might need to tweak what the tool does. You might need to troubleshoot. You might switch to a different vendor that doesn’t have an automated deployment tool. A lot of developers use a build ...