Important concepts behind Spring MVC

Now that we have completed an example with Spring MVC, we are ready to understand the important concepts behind Spring MVC.

RequestMapping

As we've discussed in earlier examples, a RequestMapping is used to map a URI to a Controller or a Controller method. It can be done at class and/or method levels. An optional method parameter allows us to map the method to a specific request method (GET, POST, and so on).

Examples of request mapping

A few examples in the upcoming sections illustrate the variations.

Example 1

In the following example, there is only one RequestMapping in the showPage method. The showPage method will be mapped to GET, POST, and any other request types for URI /show-page:

    @Controller 
    public class UserController { 
      @RequestMapping(value = "/show-page") 
      public String showPage() { 
        /* Some code */ 
       } 
    }

Example 2

In the following example, there is a method defined on RequestMapping--RequestMethod.GET. The...