Q:	Q: So, um, where’s that “redeploy” button on Tomcat?
A:	A: With Tomcat, there isn’t a one-button, really simple admin tool for deployment and redeployment (although there is an admin tool that ships with Tomcat). But think about it—what’s the worst you have to do to change the servlet’s init parameters? You make a quick change to the web.xml file, shut down Tomcat (bin/shutdown.sh), then restart Tomcat (bin/startup.sh). On restart, Tomcat looks in its webapps directory, and deploys everything it finds there.
Q:	Q: Sure it’s easy to tell Tomcat to shutdown and startup, but what about the web apps that are running? They all have to go down!
A:	A: Technically, yes. Taking your web apps down so that you can redeploy one servlet is a little harsh, especially if you have a lot of traffic on your web site. But that’s why most of the production-quality Web Containers let you do a hot redeploy, which means that you don’t have to restart your server or take any other web apps down. In fact, Tomcat does include a manager tool that will let you deploy, undeploy, and redeploy entire web apps without restarting Tomcat. In a production environment, that’s what you’d use. But for testing, it’s easier to just restart Tomcat. Info on the management tool is at: http://jakarta.apache.org/tomcat/tomcat-5.0-doc/manager-howto.html But in the real world, even a hot redeploy is a Big Deal, and taking even a single app down just because the init parameter value changed can be a bad idea. If the values of your init parameters are going to change frequently, you’re better off having your servlet methods get the values from a file or database, but this approach will mean a lot more overhead each time your servlet code runs, instead of only once during initialization.