What is Struts Technology?

Apache Struts is a powerful, open-source framework designed to help developers build robust and maintainable Java web applications using the Model-View-Controller (MVC) architectural pattern. It stands as a testament to efficient web development, simplifying complex tasks and promoting best practices.

What is Apache Struts?

At its core, Apache Struts is a free, open-source, MVC framework for creating elegant, modern Java web applications. It provides a well-defined structure for organizing code, making development faster, more organized, and easier to maintain. By abstracting away much of the underlying Servlet API, Struts allows developers to focus on business logic rather than low-level request and response handling.

Key Features and Principles

Struts is built upon several foundational principles and offers a rich set of features that streamline web application development:

• Model-View-Controller (MVC) Architecture: Struts strictly adheres to the MVC pattern. This separates an application into three interconnected components:

  • Model: Represents the application's business logic and data.
  • View: Responsible for displaying information to the user (typically JSPs or HTML).
  • Controller: Manages user input, interacts with the Model, and selects the appropriate View to display.
    This separation of concerns enhances maintainability, testability, and scalability.

• Convention Over Configuration: A significant principle Struts favors is convention over configuration. This means that by following certain naming conventions and structural patterns, developers can reduce the amount of explicit configuration needed. This leads to less boilerplate code and increased productivity, as the framework intelligently handles common tasks based on these conventions.

• Extensible Plugin Architecture: Struts is highly extensible, utilizing a robust plugin architecture. This allows developers to easily integrate new features and functionalities into their applications without altering the core framework. The framework itself ships with plugins to support modern web development needs, including:

  • REST: For building stateless, scalable web services.
  • AJAX (Asynchronous JavaScript and XML): For creating dynamic and interactive user interfaces without full page reloads.
  • JSON (JavaScript Object Notation): For lightweight data interchange, often used with AJAX.

• Powerful Tag Library: Struts provides custom JSP (JavaServer Pages) tag libraries that simplify view layer development. These tags allow developers to generate HTML forms, input fields, and display data with minimal Java code directly in JSPs, promoting cleaner separation between presentation and logic.

• Form Handling and Validation: It offers robust features for handling HTML form submissions, including automatic data population into Java objects (ActionForms in Struts 1, POJO Actions in Struts 2) and comprehensive server-side validation capabilities to ensure data integrity.

How Struts Works (Simplified Request Flow)

When a user interacts with a Struts application, a typical request follows a structured flow:

1. User Request: The user's web browser sends an HTTP request to the web server.
2. Controller (Filter/Servlet): The request is intercepted by a central Struts controller (e.g., FilterDispatcher in Struts 2 or ActionServlet in Struts 1).
3. Action Mapping: The controller consults the Struts configuration to determine which Action class (or method) is responsible for handling that specific request.
4. Action Execution: The identified Action class executes its business logic. This often involves interacting with the Model to retrieve or update data.
5. Result Determination: The Action returns a "result" string, indicating the outcome of the operation (e.g., "success," "failure").
6. View Selection: Based on the Action's result, the controller selects the appropriate View (e.g., a JSP page).
7. Response to User: The View is rendered, potentially displaying data from the Model, and sent back to the user's browser.

Struts 1 vs. Struts 2: A Brief Overview

It's important to distinguish between Struts 1 and Struts 2, as they represent different generations and architectural approaches:

Feature	Struts 1	Struts 2
Origin	Built on Servlet API; older architecture	Based on WebWork 2 framework; newer architecture
Action Class	Extends Action class	Plain Old Java Objects (POJOs)
Form Handling	Uses ActionForm objects	Uses POJO properties directly, no ActionForm
Request Scope	ActionForm is request-scoped	Action objects are request-scoped
Interceptors	No built-in interceptor concept	Highly extensible via interceptor stack
Configuration	XML-centric (struts-config.xml)	XML, Annotations, or both (struts.xml)

While Struts 1 was widely used, Struts 2 is the modern iteration and the one generally referred to when discussing "Struts technology" today. Struts 2 offers improved flexibility, easier testing, and leverages modern Java features.

Practical Insights and Benefits

Using Struts offers numerous advantages for Java web development:

• Improved Maintainability: The MVC pattern and clear separation of concerns make applications easier to understand, debug, and update.
• Code Reusability: Components like Action classes and validators can be reused across different parts of an application, saving development time.
• Enhanced Productivity: Features like convention over configuration, tag libraries, and plugins accelerate the development process.
• Scalability: The modular design of Struts applications makes them more adaptable to growth and increased user loads.
• Community Support: As a long-standing Apache project, Struts has a wealth of documentation, tutorials, and an active community, though its peak popularity has shifted to newer frameworks.

In essence, Struts technology provides a solid foundation for building organized, scalable, and maintainable Java web applications by enforcing architectural patterns and offering a comprehensive set of tools and features.