Struts Interview Questions and Answers for freshers

1. What is Struts?

   • Answer: Struts is a free, open-source framework for creating Java web applications. It's based on the Model-View-Controller (MVC) architectural pattern, helping developers organize their code and build maintainable, scalable applications. It simplifies the development process by providing reusable components and a structured approach to web application development.

2. What is MVC architecture? Explain its components in the context of Struts.

   • Answer: MVC stands for Model-View-Controller. In Struts:
     • Model: Represents the business logic and data of the application. This typically involves JavaBeans or other data objects that encapsulate data and business rules.
     • View: The user interface (UI) that displays information to the user and collects user input. In Struts, this is often JSP (JavaServer Pages) or other templating technologies.
     • Controller: Manages the flow of the application. In Struts, the controller is the core of the framework, handling requests, processing them, and interacting with the model and view.

3. Explain the role of ActionServlet in Struts.

   • Answer: ActionServlet is the heart of the Struts framework. It acts as the central controller, receiving all incoming HTTP requests. It then uses the struts-config.xml file to determine which Action class to invoke based on the request path. Essentially, it's the front controller that dispatches requests to appropriate Action classes.

4. What is an Action class in Struts?

   • Answer: An Action class is a core component in Struts that handles user requests. It extends the `org.apache.struts.action.Action` class and contains the `execute()` method, where the business logic is implemented. The `execute()` method processes the request, interacts with the model, and determines which view to display.

5. What is struts-config.xml?

   • Answer: `struts-config.xml` is the configuration file for Struts applications. It defines the mappings between URLs, Action classes, and JSP pages. It also specifies form beans, data sources, and other configuration settings for the framework.

6. What are ActionForms in Struts?

   • Answer: ActionForms are JavaBeans that encapsulate the data submitted by HTML forms. They provide data validation and simplify data handling within the Action classes. They are crucial for transferring data between the view and the controller.

7. Explain the use of ActionForward in Struts.

   • Answer: An ActionForward object represents a navigation path within the Struts application. It specifies the logical name of a JSP page or another resource to be displayed after an Action class has processed a request. It helps to decouple the Action class from specific page paths.

8. What are the different scopes in Struts?

   • Answer: Struts supports different scopes for storing data:
     • Request scope: Data is available only for the current HTTP request.
     • Session scope: Data is available for the duration of the user's session.
     • Application scope: Data is available to all users of the application.

9. How do you handle exceptions in Struts?

   • Answer: Struts allows for exception handling through the use of exception handlers configured in `struts-config.xml`. These handlers can specify which page to display in case of specific exceptions, providing a more robust and user-friendly error handling mechanism.

10. What are Interceptors in Struts?

    • Answer: Interceptors are pieces of code that are executed before or after an Action is executed. They are used to implement cross-cutting concerns like logging, security, or data validation, without cluttering the Action class itself. They enhance modularity and maintainability.

11. How does Struts handle file uploads?

    • Answer: Struts provides a mechanism for handling file uploads through the use of the `Commons-FileUpload` library. This involves configuring the appropriate settings in `struts-config.xml` and using specific properties within the ActionForm to access the uploaded file data.

12. Explain the difference between Struts 1 and Struts 2.

    • Answer: Struts 2 is a significant upgrade from Struts 1. Key differences include: Struts 2 uses a more streamlined approach with value stack and OGNL, offering better performance and improved features; it uses a more convention-based approach for configuration. Struts 2 also provides better support for AJAX and improved integration with other technologies.

13. What are the advantages of using Struts?

    • Answer: Struts offers several advantages, including a structured MVC architecture for better organization, reusable components, simplified development process, a large community and ample resources, and built-in features like validation and internationalization.

14. What are the disadvantages of using Struts?

    • Answer: While powerful, Struts can be complex for beginners, especially Struts 1. The XML configuration can be verbose. Modern frameworks may offer simpler alternatives. Moreover, Struts 1 is considered largely outdated.

15. What is the role of Tiles framework in Struts?

    • Answer: Tiles is a templating framework often used with Struts to improve code reusability and maintainability by allowing you to define reusable page components (tiles) that can be assembled to create complete pages. It helps in creating consistent layouts.

16. How do you perform validation in Struts?

    • Answer: Validation in Struts can be done using either the built-in validation framework (using validation.xml or annotations) within ActionForms or through custom validation logic in the Action classes themselves. The framework provides support for both client-side and server-side validation.

17. Explain the concept of dynamic form creation in Struts.

    • Answer: Dynamic form creation in Struts allows the creation of forms whose contents are not statically defined, but rather dynamically generated based on data from the model. This is useful when dealing with varying form structures or extensive data entry processes.

18. How do you handle internationalization in Struts?

    • Answer: Struts supports internationalization (i18n) through the use of resource bundles, which store localized strings. The framework provides mechanisms for selecting the appropriate resource bundle based on user preferences, allowing applications to support multiple languages.

19. What are the different types of validators available in Struts?

    • Answer: Struts provides a variety of validators including required, length, email, and many others, customizable through validation.xml or annotations. You can also create custom validators to implement application-specific rules.

20. How can you integrate Struts with other frameworks?

    • Answer: Struts can be integrated with other frameworks, such as Spring or Hibernate, to create a more comprehensive and powerful application architecture. This integration often involves using dependency injection and other design patterns.

21. Explain the concept of a plug-in architecture in Struts 2.

    • Answer: Struts 2 leverages a plugin architecture allowing developers to add and extend the functionality of the framework without modifying the core code. Plugins introduce custom components or functionalities into the application.

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