- Spring Boot의 MVC(Model-View-Controller) 패턴Korean version of this document is available
- Spring Boot のモデル ビュー コントローラー (MVC) パターンJapanese version of this document is available
- Spring Boot 中的模型-视图-控制器 (MVC) 模式Chinese Simplified version of this document is available
¶ The Model-View-Controller (MVC) Pattern in Spring Boot
The Model-View-Controller (MVC) is an architectural software design pattern that separates an application into three main logical components: the model, the view, and the controller.
The MVC pattern is commonly used in web applications to separate the presentation layer (the view) from the business logic (the model) and the control flow (the controller). This separation of concerns keeps the codebase clean and maintainable, and makes it easier to test and scale the application.
In a Spring MVC application, the controller is responsible for handling user requests and generating the appropriate response. The view is responsible for rendering the response to the user. The model is a data structure that stores the data to be displayed in the view.
The MVC pattern is not limited to web applications. It can be used in any type of application, including desktop, mobile, and web.
¶ How Does the MVC Pattern Work?
When a user request comes into the application, the controller is responsible for handling it. The controller determines which view to render, and passes the data to be displayed in the view to the view. The view then renders the response to the user.
The MVC pattern has the following benefits:
- It separates the concerns of the application, making the codebase easier to maintain and test.
- It makes it easier to scale the application.
- It makes it easier to add new features to the application.
¶ Implementing the MVC Pattern in Spring Boot
Spring Boot is a popular Java web application framework that makes it easy to create stand-alone, production-grade Spring-based applications.
Spring Boot MVC applications are typically organized into the following three layers:
- The controller layer
- The service layer
- The repository layer
The controller layer is responsible for handling user requests and generating the appropriate response. The service layer is responsible for business logic. The repository layer is responsible for data access.
The following diagram shows the relationship between the three layers:
In a Spring Boot MVC application, the controller is typically a Spring @RestController. The service layer is typically a Spring @Service. The repository layer is typically a Spring @Repository.
The following code snippets show how to annotate a controller, service, and repository:
@RestController
public class HelloController {
@RequestMapping("/hello")
public String hello() {
return "Hello, world!";
}
}
@Service
public class HelloService {
public String getHelloMessage() {
return "Hello, world!";
}
}
@Repository
public class HelloRepository {
public String getHelloMessage() {
return "Hello, world!";
}
}
¶ Conclusion
The MVC pattern is a popular software design pattern that separates an application into three main logical components: the model, the view, and the controller.
In a Spring MVC application, the controller is responsible for handling user requests and generating the appropriate response. The view is responsible for rendering the response to the user. The model is a data structure that stores the data to be displayed in the view.
The MVC pattern has the following benefits:
- It separates the concerns of the application, making the codebase easier to maintain and test.
- It makes it easier to scale the application.
- It makes it easier to add new features to the application.