Eclipse: Tomcat FileNotFoundException

After happily using the sysdeo Tomcat plugin for years. I’ve finally been pushed into using the Server facility bundled into Eclipse Ganymede’s JEE drop. For some reason, once started, sysdeo cannot be stopped or restarted – it loses track of the logfile classes.

In theory, you just create a new server of your choice in the Eclipse Servers View. In practice, it’s not quite so simple. Here’s why:

Tomcat actually consists of 2 aspects: a sharable codebase (CATALINA_HOME) and a per-instance part (CATALINA_BASE). This allows multiple copies of Tomcat to run on a single server using one codebase. Most of the time, CATALINA_HOME and CATALINA_BASE are the same value, since more often than not, only one copy of a given version of Tomcat is is use – at least on a developer’s machine.

When you create a Tomcat server using the Eclipse Servers facility, however, it clandestinely creates its own CATALINA_BASE, copying selected files – and only those files into a directory owned by the plugin.

I got burned. I was keeping a file of my own in CATALINA_HOME and using a relative reference to it in server.xml. The file didn’t copy and Tomcat didn’t start clean.

The simplest solution was to edit server.xml and replace the relative path to an absolute path, so that the copied configuration would be able to locate the original (and in this case, the only) copy of my file.

Apparently, however, the copying of the CATALINA_BASE data occurs only when you create a new Server definition. I had to delete the old Server definition from Eclipse and create a new one to get the changes to take.