Struts interview questions 2

6.What is ActionServlet?

ActionServlet is a simple servlet which is the backbone of all Struts applications. It is the main Controller component that handles client requests and determines which Action will process each received request. It serves as an Action factory – creating specific Action classes based on user’s request.

7.What is role of ActionServlet?

ActionServlet performs the role of Controller:

• Process user requests
• Determine what the user is trying to achieve according to the request
• Pull data from the model (if necessary) to be given to the appropriate view,
• Select the proper view to respond to the user
• Delegates most of this grunt work to Action classes
• Is responsible for initialization and clean-up of resources

8.What is the ActionForm?

ActionForm is javabean which represents the form inputs containing the request parameters from the View referencing the Action bean.

9.What are the important methods of ActionForm?

The important methods of ActionForm are : validate() & reset().

10.Describe validate() and reset() methods ?

validate() : Used to validate properties after they have been populated; Called before FormBean is handed to Action. Returns a collection of ActionError as ActionErrors. Following is the method signature for the validate() method.

public ActionErrors validate(ActionMapping mapping,HttpServletRequest request)

reset(): reset() method is called by Struts Framework with each request that uses the defined ActionForm. The purpose of this method is to reset all of the ActionForm's data members prior to the new request values being set. 

public void reset() {}