Chapter 8. The Host Component

In this chapter, we're going to continue our exploration of the Tomcat containers, focusing now on the Host component.

This component is more appropriately described as a 'virtual host'. This distinction is important as it clarifies that there is often no separate physical host that is represented by this component. Instead, while a virtual host might seem very real to the users wishing to access it, in reality, it may only be one out of a number of virtual hosts that are supported by a single physical host.

Being a container, a virtual host may contain children, which in this case are web application contexts.

The standard container pattern of an implementation class with its basic valve is extended in this chapter to also include a configuration class. This configuration class, called variously as the 'configurator' or 'deployer', registers itself as a lifecycle listener of a Host, and provides support services that are central to the purpose of the container...