JavaServer Faces will go through several processes when it processes a single request.
Restore View
Finds or creates a tree of components for the selected view. Some component, like “HtmlCommandButton”, will generate action events in this phase.
Apply Request Value
Updates the value of the components to equal ones sent in the request, optionally using convertors. Also generates events from request parameters.
Process Validations
Asks each components to validate itself (which may include using external validators).
Update Value Model
Updates all the values of backing beans or model objects associated with components. Conversion error messages
may be reported.
Invoke Application (core phase)
Calls any registered action listeners. The default action listener will also execute action methods referenced by command components (like HtmlCommandButton) and choose the next view to be displayed.
Render Response
Displays the selected view using the current display technology (like JSP).
