Sample Java HTTP Servlet

As a branch on my sample-java-project, I recently put together a sample HTTP servlet project,

git clone -b servlet git://

It’s a barebones Java HttpServlet project. All you need is a JDK, Ant, and Ivy. You don’t actually need to install a servlet container ahead of time. Instead, Jetty is fetched by Ivy and run locally from the repository’s working directory. Once you clone, you can see all this in action with the run target.

ant run

When it’s all done spewing build logs at you, visit your local machine on port 8080 with your browser. It demonstrates session tracking by a cookie, a visitor counter, and an example JavaServer Pages (JSP) page. That touches all the fundamentals.

I had spent awhile working out a development workflow with Java servlets until I came down to this one. I started out with Jetty, since it seemed like a simpler, cleaner solution than Apache Tomcat. I quickly found out that Jetty doesn’t really directly support hot deployment: updating the servlets without restarting the entire server. That’s not a good workflow. Adding any additional steps to the development loop is just asking for headaches. Tomcat supports hot deploy, but it requires significant ahead-of-time configuration for each machine I would develop on. The whole point of using Ivy is that it sets up the project’s environment for me, so I (or someone else) can quickly get going on a new machine once Ivy and Ant are in place.

So I ended up with something very much like my normal Java workflow. I restart the server every time I want to see my changes, but I do it directly from Ant — meaning I can trigger it from within Emacs. It’s really no different from developing a normal application, except that a browser is involved.

I created this two months ago and have yet to create any servlet projects from it. That’s the point of these SampleXxxxProject projects. When I start a new Java project I just fork the sample project and I have a working build system set up for me. I didn’t have any particular servlet ideas in mind, except the possibility of rewriting my blog backend with it, which didn’t happen. As with so much of web development, I think it’s just too clunky for me to be interesting in doing anything interesting with it. If I ever need to do something like this at work, I’ll at least have a head start.

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null program

Chris Wellons