The Code Chronicles: Full-Stack Edition

Featuring Spring Boot + React

Spring Web MVC: Bringing Structure to Web Applications

Spring Web MVC is a powerful and flexible framework for building web applications following the Model-View-Controller (MVC) architecture. It is like the back bone of structured web applications. It provides a clean separation between business logic and UI, making applications modular and maintainable. Spring MVC simplifies handling HTTP requests by using controllers, and its built-in support for RESTful APIs makes it the perfect choice for modern applications.

One of its biggest strengths is its robust request-handling mechanism. With annotations like @Controller and @RequestMapping, developers can easily define endpoints and handle requests without writing complex servlets. It also integrates seamlessly with templating engines like Thymeleaf, JSP, and frontend frameworks like React and Angular—offering flexibility for any full-stack project.

• What It Does: It follows the MVC architectural pattern, ensuring separation of concerns, making applications modular and maintainable. The DispatcherServlet acts as the front controller, delegating requests to appropriate handlers.
• Key Benefits: It provides built-in support for REST APIs, request validation, and declarative exception handling. This reduces boilerplate code and improves efficiency.
• Why Use It? Compared to traditional servlets and JSP, Spring Web MVC offers better scalability, easier testing, and enhanced security, making it the go-to choice for Java web development.

If you're ready to unravel what makes Spring indispensable in modern software development, let’s dive in! To make these concepts more tangible, we'll demonstrate Spring Web MVC, 3-Tier Architecture, and the flow of Spring MVC through a Prison Management System project. With the help of diagrams and hands-on implementation, we'll see how Spring simplifies development compared to traditional JDBC, making our application more scalable and maintainable.

Components of Spring Web MVC:

1. Model: It holds application data. The data can be either a single object or a list of objects.
2. Controller: It contains business logic of application.
3. View: View represents the provided information in a particular format. View means JSP file, JSP file contains either JSP or JSTL code.
4. Front - Controller: In Spring MVC, DispatcherServlet will be acted as FrontController. It will take the incoming request and map it to the right resource(view).

Understanding 3-Tier Architecture in Enterprise Applications

A 3-tier architecture structures an application into three logical layers:

1. Presentation Layer (Frontend/UI) – Handles UI and user interactions.
2. Business Logic Layer (Service Layer/ Backend Services) – Processes requests, executes business rules, and interacts with databases.
3. Data Layer (Database & Storage/Repository Layer) – Manages data operations, stores and retrieves application data efficiently.

• Advantages: Enhances scalability, security, and code maintainability by keeping each layer independent and reusable. For example, a change in the frontend doesn't affect the database layer, and business logic remains independent.
• Real-World Impact: Companies use this architecture to handle millions of requests per second, ensuring seamless performance and flexibility. Spring Boot naturally supports this structure, making enterprise-level development clean and efficient.

Flow of Spring Web MVC: How It Works Behind the Scenes and How Requests Are Processed

Spring MVC follows a well-defined flow to handle web requests efficiently, ensuring a structured execution of user inputs.

1. Client Sends Request → The user interacts with the frontend (e.g., clicks a button to view inmate details). This triggers an HTTP request that gets sent to the backend.
2. DispatcherServlet Receives Request → Spring’s DispatcherServlet, the heart of the MVC flow, intercepts the request(in the form of a URL) and decides what to do next. The DispatcherServlet will get an entry in web.xml(deployment descriptor) using the servlet tag.
3. Handler Mapping Identifies Controller → Based on the request URL and annotations (@RequestMapping or @GetMapping), Spring determines which controller should handle the request.
4. Controller Executes Logic → The mapped controller processes the request, calls service layers if needed (e.g., fetching an inmate’s details), and prepares the response.
5. Model & View Resolver→ The controller wraps the data into a model and decides on a view (HTML, JSP, JSON, Thymeleaf, etc.), ensuring the right format for the response. The DispatcherServlet will check the entry of ViewResolver in the xml file based on ModelAndView Object.
6. Response Sent to Client → The processed data is returned, and the frontend displays it—whether it’s inmate details, staff records, or a visitor log update.

This systematic approach ensures a smooth, structured request lifecycle, making debugging and maintenance easier. This structured flow improves maintainability, ensures clean separation of concerns, and enhances performance by optimizing request processing.

Annotations

Here, let's see some of the important annotations that are frequently used:

• @Controller - Class level annotation, used to represent Controller class, business logic oe server-side code written in it.
• @RequestMapping - Method level annotation, used to map a specific URI and HTTP method(GET, POST, PUT, DELETE). Ex: @GetMapping, @PostMapping, @PutMapping, @DeleteMapping
• @ResponseBody - Method level annotation, used to display response or output of type HTTPResponse on the browser.
• @RequestParam - Used to pass one or more value to the URL using param names.
• @PathVariable - Used to pass one or more value to the URL without using param names.

Why Choose Spring Over JDBC? (Solving the Limitations of JDBC)

JDBC (Java Database Connectivity) has been the standard for database interactions, but Spring provides a much better approach with ORM frameworks like Hibernate. JDBC comes with challenges:

• Boilerplate Code – Requires extensive code for even basic operations.
• Exception Handling – Error handling is repetitive and cumbersome.
• Hardcoded Queries – Makes the code less flexible and harder to maintain.

Spring, on the other hand, provides Spring JDBC & Spring Data JPA, which simplify database interactions:

? Less Code – No need to write long, repetitive JDBC code.

? Transaction Management – Automatic rollback and commit handling.

? ORM Support – Works with Hibernate and JPA, reducing SQL dependency.

? Security & Performance – Handles database connections efficiently.

? Simplifies Database Interactions: Automates transactions, connection pooling, and exception handling.

? Boosts Performance: Reduces redundant code, allowing developers to focus on business logic instead of low-level database operations.

With Spring, applications become more scalable, cleaner, flexible, secure, and more efficient applications making it the preferred choice for modern Java applications.

Spring MVC

While controllers handle incoming requests, they shouldn’t directly deal with database operations or business logic. To maintain a clean architecture, we separate concerns using Service Layers for business logic and DAO (Data Access Object) Layers for database interactions. Let’s break it down!

• Data Access Object (DAO) Layer: It's a design pattern in Java, which will provide an interface to interact with data source such as RDBMS, ORM.
• Service Layer: The service layer will separate frontend, middleware, database logic(DOA), transaction management, security.

Annotations in Spring MVC

• @Configuration - Used to indicate that a class contains one or more @Bean methods and maybe processed by the Spring IOC Container to generate Bean Definitions and process them at run time.
• @EnableTransactionManagement - Used to enable transaction management to manage transactions on the database.
• @Transactional - Used to commit the transactions whenever you perform any DML operations.

With this deep dive into Spring Web MVC, 3-Tier Architecture, and the flow of Spring MVC, you will now have a solid grasp of how these concepts come together to build scalable and maintainable applications. Understanding these principles is key to mastering backend development, and applying them in real-world projects will take your skills to the next level.

And we’re just getting started! Next up, we’ll explore Spring Batch, a powerful framework for handling large-scale batch processing. From structuring batch jobs to building fault-tolerant workflows, we’ll cover everything you need to streamline enterprise operations. For hands-on experience, I’ll be uploading this Prison Management System project on GitHub—so be sure to check it out!

A heartfelt thank you to my mentor, Jonnalagadda Surya Kiran , whose unwavering support and depth of knowledge continue to shape my learning journey. The clarity and insight he brings to complex topics have made a world of difference in my growth as a developer. For deeper insights into Spring and Java, check out his YouTube channel, Web Sadhana Samyoga—it’s a goldmine of backend development wisdom! I genuinely appreciate the guidance he provides, and I’m incredibly fortunate to be learning from him.

Let’s keep learning, building, and pushing forward—one project, one article at a time! See you in the next one. ??

What’s been your biggest takeaway from this article? I’d love to hear your thoughts!

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