Spring MVC is a Java framework that is used to develop web applications. It is built on a Model-View-Controller (MVC) pattern and possesses all the basic features of a spring framework, such as Dependency Injection, Inversion of Control. The architectural design of a Spring MVC can be used to develop flexible web applications. It basically separates the different aspects of the application, like input logic, UI logic, and business logic.
Spring is an open-source that was created to resolve the complexity of an enterprise application development. It has a layered architecture that helps the developers to select the components which can be further used while providing a cohesive framework for the process of application development. Spring framework is flexible as it supports and can be integrated with various technologies like:
- It supports the REST style of web services.
- Supports transactional management
- The developer can interact with different databases.
- Can be integrated with Object Relationship frameworks, for instance, iBatis
- Containers can resolve the required dependencies as it supports Dependency Integration.
Source: Terasoluna Global Framework
Let us now understand the above-given Spring MVC Flow diagram.
Understanding Spring MVC Flow Diagram
The first step in the MVC flow is when a request is received by the Dispatcher Servlet.
2. Dispatcher Servlet
Now, the Dispatcher Servlet will with the help of Handler Mapping understand the Controller class name associated with the received request. Once the Dispatcher Servlet knows which Controller will be able to handle the request, it will transfer the request to it.
The Controller will process the request based on appropriate methods and will return it to Model Data and View Name.
4. Model and View
It will return the processed data to the Dispatcher Servlet.
5. View Resolver
Once Model and View receive the data, Dispatcher Servlet will transfer it to the View Resolver to get the actual view page.
Finally, the Dispatcher Servlet will pass the Model object (results) to the view page. This is the final step of the flow where the results will be displayed.
Let us understand the process with the help of an example.
For instance, the user wants to buy a t-shirt. Here, the user can view, add to cart, and purchase the item or even remove it from the list. Firstly, the request will be sent by the user, which will be processed by Dispatcher Servlet. The Dispatcher Servlet will study the class of request and will send it to the relevant controller. Let’s say the Controller, in this case, is “tshirt_controller.php”. Now, the controller “tshirt_controller.php” will pick up a suitable view and will present the data to Model and View. Here, it will be sent to Dispatcher Servlet again, which will send the results to View.
Advantages of Spring MVC
- Different roles: The Spring MVC has separate roles which can be fulfilled with the help of a specialized object. The roles involved in this are command object, model object, controller, dispatcher servlet, view resolver, validator, and more.
- Lightweight: The container used for the development and deployment of applications uses a lightweight servlet.
- Fast development: The MVC spring framework enables rapid and parallel development. It helps the developer to complete the project on time.
- Strong and powerful configuration: It provides powerful configuration for application and framework classes. These configurations include easy simple referencing like business objects and web controllers.
- Business code: It provides reusable business codes that allow the developer to use existing business objects instead of creating new objects.
- Easy testing: Spring generally uses Java Beans that allows the developer to inject data using easy methods.
- Mapping: It provides flexible mapping that allows the page to redirect easily.
- Dependency Injection: Inversion of Control or dependency injection allows the developer to not create a complete environment for the dependencies.
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Spring MVC framework is a crucial part for you as a developer as it can help you to attain new heights in your career. It provides an entirely new level to your application, which is more transparent and can be maintained easily. Here is the list of must-know interview questions regarding Spring MVC that will help you to get your dream job. If you are interested to learn more and need mentorship from industry experts, check out upGrad & IIIT Banglore’s PG Diploma in Full-Stack Software Development.