Struts View Components
The last of the MVC components to discuss are the view components. Arguably, they are the easiest to understand. The view components typically employed in a Struts application are:
Data transfer objects
Java resource bundles
Using the Struts ActionForm
ActionForm objects are used in the
framework to pass client input data back and forth between the user
and the business layer. The framework automatically collects the
input from the request and passes this data to an
Action using a form bean, which then can be passed
along to the business layer. To keep the presentation layer decoupled
from the business layer, you should not pass the
ActionForm itself to the business layer; rather,
create the appropriate DTO using the data from the
ActionForm. The following steps illustrate how the
framework processes an
ActionForm for every request:
Check the mapping for the action and see if an
ActionFormhas been configured.
ActionFormis configured for the action, use the
nameattribute from the
actionelement to look up the form bean configuration information.
Check to see if an instance of the
ActionFormalready has been created.
ActionForminstance is present in the appropriate scope and it’s the same type as needed for the new request, reuse it.
Otherwise, create a new instance of the required
ActionFormand store it in the appropriate scope (set by the
scopeattribute for the
Call the ...