versions of MVC

[prashanth nagaraj]

Can anyone tell me the various versions of MVC w.r.t to Java , What is the current version??

[Junilu Lacar]

If you refer to the Model-View-Controller design pattern, it is not a product so there are really no "versions" of it.
Struts, discussed heavily in the Java Frameworks forum, is a framework that is based on the MVC pattern. Struts is now at 1.1 beta 3. The last stable production release was 1.0.2. Swing is also based on MVC. These are just two examples of how the pattern can be implemented in different ways.
[ February 06, 2003: Message edited by: Junilu Lacar ]

[Marc Peabody]

In a way, patterns can be like a religious text that can be interpreted in different ways by different people.
I could be wrong, but this is how I understand MVC:
MVC began as an three-tier architectural pattern...
Model - Database
View - GUI with access to Controller tier
Controller - business logic to link client with dynamic data from the database
With regards to Java, as in your question, depends on if you include J2EE. If this is so, the trend in J2EE is to have a five-tier architecture...
Client (Web Browser)
Presentation (*will talk about soon)
Business (Processes info between Pres. & Int.)
Integration (Accesses Database)
Resource (Database)
*The presentation tier includes things like Servlets, JSP, and Javabeans (not EJB). The MVC is used as a design pattern within the presentation tier. The main purpose of using MVC is to make code in the tier more reusable. The best illustration I've seen of MVC in relation to J2EE comes from the SCWCD Exam Study Kit book - the chapter on Design Patterns. This book is really as essential to have as the saloon.
Since MVC isn't necessarily a "product" there is some vagueness to it, so don't read just one interpretation of it and agree with what you hear. Just like religion or philosophy, listen to points from many sources and arrive at what seems to be truth. I hope the people that don't agree with my definition of MVC can present their view with an open mind - I hate being told that I'm the Anti-Pattern!

[Ilja Preuss]

Here is my understanding of MVC:
Model: Classes representing the business rules of the system
View: Classes representing presentation logic - how the model will be viewed to the user
Controller: Classes handling user interaction - getting key presses and mouse clicks from the user and deciding how model and view should react to them.
The idea behind MVC is that if you want to change the way the user interacts with the system, you don't have to change the Model at all.
A google search should give you *much* more information...