How do Tomcat examples work?

Question

Alright, this is a very simple question. I just installed Tomcat 6 on my Mac to play around with it, and every tutorial I look at says the first thing to do to create a new web application is to add a line to the server.xml file with defines a new Context. Fair enough. However, my question is, I don't see a line in there for the example web applications, so how do those work?

Answer 1

The sample web applications use the default host defined in $CATALINA_HOME/conf/server.xml:

<!-- Define the default virtual host
       Note: XML Schema validation will not work with Xerces 2.2.
   -->
  <Host name="localhost"  appBase="webapps"
        unpackWARs="true" autoDeploy="true"
        xmlValidation="false" xmlNamespaceAware="false">
  ...
  </Host>

Notice the appBase attribute (which is defined relative to $CATALINA_HOME). If you drop a .war file in that folder, it will be auto-deployed as a context in the default host. Tomcat will dynamically create a context if none is defined in $CATALINA_HOME/conf/server.xml (actually there are a couple of other places contexts can be defined too but that is outside the scope of this discussion).

So for example, if you drop a war file named mycontext.war in $CATALINA_HOME/webapps, you'll be able to reach it with your web browser at the url http://localhost:8080/mycontext/ (assuming you haven't changed the default port and autoDeploy settings that tomcat ships with). This is how the examples that ship with tomcat are set up.