Struts Interview Questions And Answers

The main purpose of using MVC pattern is to decouple the GUI from the Data. It also gives the ability to provide multiple views for the same Data. MVC pattern separates objects into three important sections:-

Model: - This section is specially for maintaining data. It is actually where your business logic, querying database, database connection etc. is actually implemented.
Views: - Displaying all or some portion of data, or probably different view of data. View is responsible for look and feel, Sorting, formatting etc.
Controller: - They are event handling section which affects either the model or the view. Controller responds to the mouse or keyboard input to command model and view to change. Controllers are associated with views. User interaction triggers the events to change the model, which in turn calls some methods of model to update its state to notify other registered views to refresh their display.

Struts are an open source framework for developing JAVA web applications. It extends Java Servlets API and helps developers to adopt MVC architecture. MVC pattern is good but developing the same can be real pain. Using struts it’s a breeze to implement MVC in projects. Struts provide a standard way of implementing MVC.

Below are the folders from point of view of root folder.
META-INF: - This directory has the Meta information.
WEB-INF/classes: - This location has the actual JAVA classes.
WEB-INF/classes/ApplicationResources.properties:- Contains text which application can
use. For instance error messages.
WEB-INF/lib/struts.jar:- Contains the Struts servlet, helper classes, taglib code etc.
WEB-INF/*.tld:- The Struts tag libraries.
WEB-INF/struts-config.xml:- A Struts configuration file.
WEB-INF/web.xml:- Configuration file for the servlet container
Index.jsp:- All JSP files come in the root directory as this one Index.jsp.

just to summarize how the execution flows in the struts application.
User makes browser makes a request to the Struts application that is processed by ActionServlet (Controller).
ActionServlet (Controller) populates the ActionForm (View) object with HTML JSP form data method.
ActionServlet (Controller) executes the Action object (Controller).
Action object uses the model and does the necessary execution and passes the control back to the ActionServlet
Action (Controller) forwards control to the JSP pages.
JSP pages use model data to generate a response to the browser.