Model 1 and Model 2 (MVC) Architecture

Misconceptions

 
Student: Master,  what is the difference between MVC 1 and MVC 2 ?
Master: Grasshopper, there is no such thing as MVC 1 and MVC 2, there’s just MVC. if you meant to ask about the difference between Model 1 and Model 2 with respect to web applications, then this article will help you out.
 
In Java there are two types of programming models

1. Model 1 Architecture
2. Model 2 (MVC) Architecture

 
** UPDATE: Struts 2 Complete tutorial now available here.
 

Model 1 Architecture

Flow of the Model 1 architecture.

1. Browser sends request for the JSP page
2. JSP accesses Business service Bean class and invokes business logic
3. Business service Bean class connects to the database to store/retrieve data
4. Response generated by JSP is sent to the browser

 
Disadvantage
Navigation control is decentralized
 

Model 2 (MVC) Architecture

Model 2 is based on the MVC (Model View Controller) design pattern.

• Model         – Represents the data and business logic of the application.
• View          – Represents the presentation.
• Controller   – The controller module acts as an interface between view and model.

It intercepts all the requests i.e. receives input and commands to Model / View to change  accordingly.
 
Advantage of Model 2 (MVC) Architecture

• Navigation control is centralized (Controller only has the control to determine the next page)
• Easy to maintain, extend and test.

Disadvantage of Model 2 (MVC) Architecture
If we change the controller code, we need to recompile the class and redeploy the application.