What is an invoker servlet in a Tomcat servlet container?

Avi Kak

The "invoker servlet" is a system-supplied servlet that extracts the name of the requested servlet class from the portion of the URL that comes after "/servlet". The invoker servlet then loads the requested servlet into the container and executes it.

If you look at the contents of the webapp deployment descriptor file, web.xml, in the TOMCAT_HOME/conf directory, you will find the following servlet element at the beginning:


which declares the name and the place of the system-supplied invoker servlet. Shortly thereafter appears the following servlet-mapping element:


which tells the container that all requests that begin with "/servlet" (relative to root of the webapp specified by the name that comes before "/servlet") are to be sent to the invoker servlet.

The highly informative posting by Craig McClanahan is the source of the information supplied here.