Spring Web MVC

 Spring Web MVC is one module available in the spring framework.

 Using Spring Web MVC module we can develop 2 types of applications.

1) Web Applications

2) Distributed Application (Webservices)

-> Web Applications will have user interface (UI).

-> Customers can access web applications directley using internet.

-> Web Applications meant for customer to business communication (C 2 B).

Ex: facebook, gmail, linkedin, naukri etc...

-> Distributed Applications are meant for Business to Business Communication ( B 2 B ).

-> If one application is communicating with another application then we call them as Distributed apps.

-> Distributed Applications we can develop in 2 ways.

1) SOAP Webservices

2) RESTFul Services

Note: SOAP Webservices & RESTFul Services can be developed using Spring Web MVC.

-> Distributed applications we are developing to re-use logic of one application in another application.

Ex:

MakeMyTrip  -----------> IRCTC

Passport  -----------> AADHAR

Gpay ---------------> Banking Apps

Swiggy  ----------> Banking Apps

Advantages of Spring Web MVC

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1) Easily we can develop web & distributed applications using Web MVC module.

2) It supports Multiple Presentation Technologies (JSP & Thymeleaf).

3) I 18 N Support (Internationalization)

4) Form Bindings ( Form Data will be binded to Object and vice versa )

5) Form Tag Library (To simplify forms development with Dynamic behvaiour)

6) Having support for XML to Java object conversion and vice versa.

7) Having support for JSON to java object conversion and vice versa.

Spring Web MVC Architecture

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1) Dispatcher Servlet (Front Controller)

2) Handler Mapper

3) Controller

4) Model And View

5) ViewResolver

6) View

-> DispatcherServlet is a pre-defined servlet class in Spring Web MVC

-> DispatcherServlet is called as Front Controller / Framework Servlet

-> It is responsible to perform pre-processing and post-processing for every request

-> HandlerMapper is a pre-defined class in spring web mvc

-> HandlerMapper is used to identify Request Handler

-> It will identify which request should be processed by which Controller class

-> HandlerMapper will identify Request Handler based on URL Pattern

-> Controller is a class which contains logic to handle request and response

-> Controller is also called as Request Handler

-> We will create Controller classes using @Controller annotation

-> Controller will return data to Dispatcher in ModelAndView object

-> Model represents Data in Key-Value pair format

-> View represents presentation logical file name

-> To display data in view file we will use ModelAndView object

-> ViewResolver is used to identify where view files available in our project

-> ViewResolver is responsible to identify physical location of view files

-> View component is used to render model data on physical view file to display that to end user