In this section, we'll look at how Tomcat implements the
Engine component. This image describes the key elements of an engine's relationships.
Every Tomcat container implements the
org.apache.catalina.Container interface. The
org.apache.catalina.core.ContainerBase class is provided as a convenience to container implementers. It not only provides default implementations for the methods in the
Container interface, but also implements other interfaces, such as the
org.apache.catalina.Lifecycle and the
org.apache.catalina.Pipeline interfaces that are critical for the functioning and administration of a container.