Controller class in spring

 To initialize the controller in the spring we need the below annotations

 @Controller:

• this is a specialization of the @Componet annotation. 
  
• the controller annotation indicates that the class is a controller type to spring while component scanning.
• by default, @Controller handler methods only return the view. 
• if we want to return JSON or XML response then need to add @ResponseBody annotation on every method in the class.
  

  
  @Controller
  public class HelloWordController {
  
     @RequestMapping("/showform")
     public String showForm() {
        return "helloword-form";
     }
  
     @RequestMapping("/showform2")
     @RequestBody
     public User showForm() {
        return new User("Nilesh","Kadam");
     }
  }
  
  

@RestController :

• @RestController is a specialized version of @Controller annotation. this is a combination of @Controller and @ResponseBody annotation.
• RestController is useful for RESTfull web service because in RESTfull web service we only return the data not view.
• in this, we do not require to add @ResponseBody on every method
  

  
  @RestController
  public class HelloWordController {
     
     @RequestMapping("/showform")
     public User showForm() {
        return new User("Nilesh","Kadam");
     }
  }