If there is any problem in software development then its design pattern is the main solution to fix this. They are like pre-defined blueprints which we use to solve object-oriented design problems in your project. Firstly it finds out where the problem is and then fixes it and also describes the procedure and its consequences. MVC and MVC2 are two different approaches to the famous MVC (Model View Controller) architecture pattern.
MVC vs MVC2
The main difference between MVC and MVC2 is that MVC is an application design model composed of three interconnected parts whereas MVC2 is a more complex pattern where uncoupling of the Application state and Presentation Control Logic is done. MVC includes the model (data), the view (user interface), and the controller (processes request). A major difference between MVC and MVC2 is complexity. In web applications of the Java world, the two common design models (Model 1 and Model 2) are closely related to MVC and are often erroneously referred to as MVC1 (or just MVC) and MVC2.
MVC was the first-generation approach in Java web applications where JavaServer Page (JSP) pages were used for user interface along with JavaBeans which could encapsulate the multiple objects in a single object to implement the MVC architecture. User requests from the browser are sent to JSP which holds the Controller logic and binds the Model for data which would update the view and send the response back to the user which gets displayed in the user interface. This approach combines Controller and View functionality within a JSP page and therefore breaks the MVC paradigm.
MVC2 was introduced by Sun Microsystem org as a design pattern that doesn’t break the MVC paradigm, unlike MVC, where business logic was separated from the views and all the client requests were handled at one place rather than in each JSP file in MVC. In the MVC2 pattern, JSP is replaced by servlets for the controller logic.
Comparison Table between MVC and MVC2
| Parameter of comparison | MVC | MVC2 |
| Definition | In MVC, a single component is responsible for receiving requests and sending responses. | In MVC2, there are multiple components for receiving requests and sending responses. i.e. Controller & View. |
| Navigation | In MVC, each JSP has a controller and view logic that determines the navigation of the next view page that makes it redistributed | In MVC2, the servlet contains the navigation logic of the next view page which makes it centralized |
| Time-consuming | Takes more time to write the code to develop the custom JSP tags to avoid scriptlet tag | Takes less time to develop as all the navigation control is centralized. |
| Independency | Business logic and presentation Logic is combined in JSP, so web designers and web developers can’t work simultaneously. | Since it has separation between the logic and view that’s why designer and developer can work together. |
| Re-usability | It is harder to reuse and extend because of tight coupling between logic and view | It’s easy to reuse and extend which is suited for bigger applications |
What is MVC?
MVC is an architectural design pattern for software design recurring problems which gives a high-level description approach to the solution. The MVC architecture has three modules: model, view, and controller.
Model: It represents the state of data (which gets displayed to the user on the view page).
View: The view module is the user interface through which the user performs the action and internally communicates to the server.
Controller: The controller module processes the user request, business logic and with the help of a model manipulates the data which gets displayed in the UI.
MVC starts with JSP accepting the client request that works together with JavaBeans for data processing logic which gets sent to the client. The job is divided between JavaBeans and JSP where JSP invokes the JavaBeans and business logic wherein JavaBeans internally calls the database to save/get the data. In the end, JSP sends back the response to the client which updates the view in the browser.
JavaBeans which are also referred to as Beans is responsible for the encapsulation of multi objects into a single object while the JSP has both the Controller and View logic. MVC is also referred to as page-centric because of its direct access to another view page which is ideal for smaller applications.
What is MVC2?
Most software engineers think that MVC2 is an improved version of MVC, like version 2.0; it isn’t. Model 1 and Model 2 were developed concurrently and are two variants of how things should be done.
MVC2 is a more complex pattern where uncoupling of the Application state and Presentation Control Logic is done. It has a controller wherein logic has been written to process all the incoming requests and required action that needs to be taken, like navigation to a different view page or updating the state of the Model.
Here, in MVC2, the servlet acts as the controller layer which is also an interface between the View layer and Model layer wherein it receives the request from client or User interface which is nothing but view layer, and processes them with appropriate validation if required. JSP has view logic that internally uses the Beans, so if servlets update the state of the model it gets reflected in the view page.
Unlike MVC, JSP in MVC2 doesn’t have both controllers and view logic; its sole responsibility is to fetch the updated state of the model from that servlet to display on the view Page.
Main Differences Between MVC and MVC2
We often confuse MVC2 as the 2.0 version of MVC, however, it’s not, it’s Java design models where MVC2 architecture is more complex and best suited for the bigger applications.
The distinguishing factor between MVC and MVC2 relations can be summed up on the following grounds:
- In MVC, a single component is responsible for receiving requests and sending responses but in MVC2, there are multiple components for receiving requests and sending responses. i.e. Controller & View.
- MVC1 tightly couples the presentation logic with the business logic but MVC 2 isolates or uncouples the presentation logic from business logic.
- In MVC Business logic and presentation Logic is combined in JSP, so web designers and web developers can’t work simultaneously but in MVC2 there is a separation between logic and view that’s why designer and developer can work together.
- In MVC 1, controller and model, both are JSP or we could say written in the same JSP. But in MVC2 the controller is servlet and the model is Java class.
- MVC Doesn’t support the reusability of application components whereas MVC2 supports reusability of components which is good for bigger and more complex applications.
Conclusion
As we saw the thick line difference between MVC and MVC2 despite having similar names but both are used as solutions for recurring system design problems.
MVC2 is more complex and has a separation of concerns which is utilized for bigger applications or intuitive user experience because of its centralized feature where all the requests are handled by one controller. Unlike the MVC where the current JSP is the one that determines the next view page to open.
MVC2 de-couples the view pages from controllers, unlike the MVC which keeps both business and view logic coupled in a JSP. Hence, the MVC2 is easier to maintain for multiple users because of its reusability and extend feature and is capable of supporting a more complicated system in real-time, like, Facebook, Instagram.
References
- https://www.scientific.net/AMM.198-199.537
- https://ieeexplore.ieee.org/abstract/document/777091/
- https://academic.oup.com/jpp/article-abstract/64/3/397/6135294