This is the main bean for the application. It maintains a
Map of CarBean instances, keyed by model name,
and a Map of CarCustomizer instances, keyed by
package name. The CarBean instances in the model
Map are accessed from several pages, as described
below.
Several pages in the application use this bean as the target of
method reference and value reference expressions.
The "storeFront" page uses value binding expressions to pull
information about four of the known car models in the store.
The "carDetail" page uses value binding expressions to pull
information about the currently chosen model. It also uses the
action attribute to convey the user's package
choices.
The "confirmChoices" page uses value binding expressions to
pull the user's choices from the currently chosen model.