What is MVC

The Model-View-Controller (MVC) is an architectural pattern that separates an application into three main logical components: the model, the view, and the controller.

Recap

Example Code

        
          public class Student {
          private String rollNo;
          private String name;

          public String getRollNo() {
            return rollNo;
          }

          public void setRollNo(String rollNo) {
            this.rollNo = rollNo;
          }

          public String getName() {
            return name;
          }

          public void setName(String name) {
            this.name = name;
          }
      }

          
              public class StudentView {
                public void printStudentDetails(String studentName, String studentRollNo){
                  System.out.println("Student: ");
                  System.out.println("Name: " + studentName);
                  System.out.println("Roll No: " + studentRollNo);
                }
             }

          
            public class StudentController {
              private Student model;
              private StudentView view;

              public StudentController(Student model, StudentView view){
                  this.model = model;
                  this.view = view;
              }

              public void setStudentName(String name){
                  model.setName(name);
              }

              public String getStudentName(){
                  return model.getName();
              }

              public void setStudentRollNo(String rollNo){
                  model.setRollNo(rollNo);
              }

              public String getStudentRollNo(){
                  return model.getRollNo();
              }

              public void updateView(){
                  view.printStudentDetails(model.getName(), model.getRollNo());
              }
            }

Advantages of MVC

Development of the application becomes fast.
Easy for multiple developers to collaborate and work together.
Easier to Update the application.
Easier to Debug as we have multiple levels properly written in the application.

Disadvantages of using MVC

It is hard to understand the MVC architecture.

Must have strict rules on methods.

Fat Controllers

The Model

The Model component corresponds to all the data-related logic that the user works with. This can represent either the data that is being transferred between the View and Controller components or any other business logic-related data.

For example, a Customer object will retrieve the customer information from the database, manipulate it and update it data back to the database or use it to render data.

The View

The View component is used for all the UI logic of the application. For example, the Customer view will include all the UI components such as text boxes, dropdowns, etc. that the final user interacts with.

The Controller

Controllers act as an interface between Model and View components to process all the business logic and incoming requests, manipulate data using the Model component and interact with the Views to render the final output.

For example, the Customer controller will handle all the interactions and inputs from the Customer View and update the database using the Customer Model. The same controller will be used to view the Customer data.