Struts Interview Questions
1. What is Struts?
Struts is a web page development framework and an open source software that helps developers build web applications quickly and easily. Struts combines Java Servlets, Java Server Pages, custom tags, and message resources into a unified framework. It is a cooperative, synergistic platform, suitable for development teams, independent developers, and everyone between.
2. Why it called Struts?
Because the designers want to remind us of the invisible underpinnings that hold up our houses, buildings, bridges, and ourselves when we are on stilts. This excellent description of Struts reflect the role the Struts plays in developing web applications.
3. Do we need to pay the Struts if being used in commercial purpose?
No. Struts is available for commercial use at no charge under the Apache Software License. You can also integrate the Struts components into your own framework just as if they were writtern in house without any red tape, fees, or other hassles.
4. What are the core classes of Struts?
Action, ActionForm, ActionServlet, ActionMapping, ActionForward are basic classes of Structs.
5. What is the design role played by Struts?
The role played by Structs is controller in Model/View/Controller(MVC) style. The View is played by JSP and Model is played by JDBC or generic data source classes. The Struts controller is a set of programmable components that allow developers to define exactly how the application interacts with the user.
6. How Struts control data flow?
Struts implements the MVC/Layers pattern through the use of ActionForwards and ActionMappings to keep control-flow decisions out of presentation layer.
7. What configuration files are used in Struts?
- ApplicationResourcesl.properties
- struts-config.xml
8. What helpers in the form of JSP pages are provided in Struts framework?
- struts-html.tld
- struts-bean.tld
- struts-logic.tld
- The Struts is not only thread-safe but thread-dependent(instantiates each Action once and allows other requests to be threaded through the original object.
- ActionForm beans minimize subclass code and shorten subclass hierarchies
- The Struts tag libraries provide general-purpose functionality
- The Struts components are reusable by the application
- The Struts localization strategies reduce the need for redundant JSPs
- The Struts is designed with an open architecture--subclass available
- The Struts is lightweight (5 core packages, 5 tag libraries)
- The Struts is open source and well documented (code to be examined easily)
- The Struts is model neutral
11. How you will make available any Message Resources Definitions file to the Struts Framework Environment? - Message Resources Definitions file are simple .properties files and these files contains the messages that can be used in the struts project. Message Resources Definitions files can be added to the struts-config.xml file through <message-resources /> tag.
Example:
<message-resources parameter="MessageResources” />
12. What is Action Class? - The Action Class is part of the Model and is a wrapper around the business logic. The purpose of Action Class is to translate the HttpServletRequest to the business logic. To use the Action, we need to Subclass and overwrite the execute() method. In the Action Class all the database/business processing are done. It is advisable to perform all the database related stuffs in the Action Class. The ActionServlet (commad) passes the parameterized class to Action Form using the execute() method. The return type of the execute method is ActionForward which is used by the Struts Framework to forward the request to the file as per the value of the returned ActionForward object.
