How does the Struts framework work?

The working principle of the Struts framework is based on the Model-View-Controller (MVC) design pattern.

In the MVC pattern, applications are divided into three core components: the Model, the View, and the Controller. In the Struts framework, the Model typically refers to the component responsible for business logic processing and data persistence, the View typically refers to the user interface, and the Controller is responsible for coordinating interaction between the Model and the View.

When a request reaches the application, the front controller of the Struts framework intercepts the request and, based on the mapping rules in the configuration file, identifies the corresponding handler (Action). The handler is responsible for processing the request, and based on the business logic, calls the appropriate model components for data processing and operation. The handler can also encapsulate the processing result into an object containing data and view names, and then pass it to the view component.

After the view component receives the processing result, it locates the corresponding view template based on the view name, fills the data into the template to generate the final user interface. Finally, the view component sends the generated user interface back to the client for display.

Throughout the process, the Struts framework establishes mappings between requests and handlers, handlers and models, and processing results and views through configuration files, enabling the distribution of requests and the display of processing results. Additionally, the Struts framework provides many utility classes and tag libraries, simplifying the development process and improving efficiency.