MVC Architecture

• To overcome the problem of Model 1 architecture, MVC architecture can be used. In this MVC architecture for each functionality we need to write separate multiple or shared servlet/ jsp and one or more model components.  

• In MVC there is clear separation among all the logics and there are 3 main components. 

1. 1. Model (M): It contains the business logic and the persistence logic. 

   2. View (V): It contains the presentation logic. 

   3. Controller(C): It contains the controller logic/Integration logic, controls Model and View. 

• The logic that is used to prepare user interface and to display results by applying styles is called presentation logic. 

• The main logic of the application that generates results based on given input values is called business logic. 

• The permanent storage unit that can store data is called persistent store. CRUD operations on the Database table - persistent store are called persistent operations. The logic used for this purpose is called persistent logic. 

• Logic that controls and monitors all the operations of MVC architecture based applications is called Integration logic. This logic contains code to perform the communications between view layer resources and model layer resources. 

• The Java class that contains purely persistence logic and separates that logic from other logics of the applications is called DAO (Data Access Object) class. Any modifications done in persistent logic of DAO will not affect other logics of the applications. 

• Below table gives the sample combinations of technologies used in applications in different layers.