Application represents a per-web-application singleton object where applications based on JavaServer Faces (or implementations wishing to provide extended functionality) can register application-wide singletons that provide functionality required by JavaServer Faces. 

ApplicationFactory is a factory object that creates (if needed) and returns Application instances. 

A NavigationHandler is passed the outcome string returned by an application action invoked for this application, and will use this (along with related state information) to choose the view to be displayed next.

A default implementation of NavigationHandler must be provided by the JSF implementation, which will be utilized unless setNavigationHandler() is called to establish a different one. 

StateManager directs the process of saving and restoring the view between requests. 

Provides a simple implementation of StateManager that can be subclassed by developers wishing to provide specialized behavior to an existing StateManager instance. 

ViewHandler is the pluggablity mechanism for allowing implementations of or applications using the JavaServer Faces specification to provide their own handling of the activities in the Render Response and Restore View phases of the request processing lifecycle. 

Provides a simple implementation of ViewHandler that can be subclassed by developers wishing to provide specialized behavior to an existing ViewHandler instance. 

FacesMessage represents a single validation (or other) message, which is typically associated with a particular component in the view. 

Class used to represent message severity levels in a typesafe enumeration.

Convenience struct for encapsulating tree structure and component state. 

Implementations must throw this FacesException when attempting to restore the view StateManager#restoreView(javax.faces.context.FacesContext, String, String) results in failure on postback.