Spring MVC (Model-View-Controller) is a framework within the broader Spring Framework that provides a comprehensive infrastructure for developing Java- based enterprise web applications. It is designed to simplify the development and maintenance of web applications by promoting a clean separation of concerns and following the Model-View-Controller architectural pattern.

Here's a brief introduction to the key components and concepts in Spring MVC:

1. Model:

• • The Model represents the application's data and business logic. It is responsible for managing the data and business rules of the application.
• • In Spring MVC, the Model is often implemented using POJOs (Plain Old Java Objects) that encapsulate the application's state.

2. View:

• • The View is responsible for rendering the data provided by the Model in a user-friendly format. It represents the presentation layer of the application.
• • In Spring MVC, views are typically implemented using technologies like JSP (JavaServer Pages), Thymeleaf, or other view templates..

3. Controller:

• • The Controller is responsible for handling user requests, processing input, and managing the flow of control between the Model and the View.
• • In Spring MVC, controllers are implemented as Java classes and are annotated with @Controller. They handle HTTP requests, perform business logic, and return a view to render the response.

4. DispatcherServlet:

• • The DispatcherServlet is the front controller in the Spring MVC framework. It receives all incoming requests and dispatches them to the appropriate controller based on the configuration.
• • It acts as the central hub for handling HTTP requests, managing the flow of control, and coordinating the interaction between the Model, View, and Controller.

5. HandlerMapping:

• • HandlerMapping is responsible for mapping incoming requests to the appropriate controller. It determines which controller should handle a specific request based on the request URL.

6. ViewResolver:

• • ViewResolver is responsible for resolving the logical view name returned by the controller to an actual view implementation (JSP, Thymeleaf template, etc.).

7. ModelAndView:

• • ModelAndView is a class that represents both the data and the view that should be rendered. It allows a controller to specify both the data and the logical view name to be rendered.

Here's a simple example of a Spring MVC controller:

@Controller
public class HelloController {

    @RequestMapping("/hello")
    public ModelAndView hello() {
        ModelAndView modelAndView = new ModelAndView("hello");
        modelAndView.addObject("message", "Hello, Spring MVC!");
        return modelAndView;
    }
}

In this example, the @Controller annotation marks the class as a controller, and the @RequestMapping annotation specifies the URL path ("/hello") that triggers the hello() method. The method returns a ModelAndView object, indicating the logical view name ("hello") and adding a message attribute to the model.